Dr. Wack "A1" A1 Cabrio "Verdeck-Reiniger" Soft top cleaner 400ml

Dr. Wack A1 Cabrio "Verdeck-Reiniger" gets the green film out of your soft top

What is Dr. Wack A1 Cabrio "Verdeck-Reiniger"? A cleaning foam in a 400 ml can for every convertible soft top, from cotton-blend fabric to vinyl, for spot cleaning or the whole roof. It's not a proofer and not a pigmented colour restorer: it won't bring back water repellency or faded colour.

Dr. Wack A1 Cabrio "Verdeck-Reiniger" is a soft top cleaner from Dr. Wack that works as a clinging power foam. The foam stays put on the sloped roof, lifts road film, green algae and individual stains out of the top layer and holds them until you rinse foam and dirt off together. The manufacturer approves it for every type of top: fabric, acrylic, Dralon, plastic and leather.

Here the form does the work, not just the chemistry. A liquid cleaner runs down a soft top in seconds and drags the loosened dirt with it into the capillaries of the fabric. Foam has a yield point — it stays where it is until a force acts on it. For you, that means the dirt travels up into the foam and leaves the roof with the rinse water, instead of soaking in one layer deeper.

Why a soft top gets dirty differently from paint is explained in Dr. Wack's product information sheet. Most tops are built in three layers: a cotton inner lining as the headliner, a rubber interlayer, and on top an outer layer of plastic, acrylic, polyacrylonitrile or cotton-blend fabric. That outer layer is rough and soft. Dirt doesn't sit on top — it snags.

And it's delicate. Dr. Wack explicitly gives soft tops a low abrasion resistance: scrubbing attacks the surface texture and colour depth before it gets to the dirt. That's exactly why a cleaner that sits for 5 minutes beats a good hard scrub. Time does the work, not pressure.

• Dwell time on the slope instead of run-off. A soft top is a sloped surface where any liquid runs off before it works. The power foam stays where you put it and can work the full 5 minutes on stubborn grime. That's the difference between one soak and three re-sprays.
• 8 to 12 complete roofs from 400 ml. Dr. Wack puts the yield for full-coverage foaming at 8 to 12 applications, compared with 2 to 6 with conventional products. If you only treat individual stains, a can goes much further, because the foam goes exactly where you aim it and nothing is wasted.
• One cleaner for five roof materials. Plastic, fabric, acrylic, Dralon and leather are all on the manufacturer's list. So in a two-convertible household you don't need a second can when a fabric top sits next to a vinyl one. According to Dr. Wack, the foam doesn't attack the factory proofing.

Day-to-day from Detailing1: We often see people aim the can at a bone-dry roof because it's quicker. It isn't quicker — it kills the effect: dry fabric soaks up the foam in seconds, and down there it doesn't work any more. Give it 2 minutes with the hose until the fabric is evenly dark, then reach for the can. And start at the seams and on the shady side. That's where water sits longest, and that's where the green film shows up first.

The power foam holds on the slope for 5 minutes

Wet the roof, rinse off loose dirt, shake the can, spray the foam onto the dirty areas and leave it for 5 minutes on stubborn grime.

Pre-wetting isn't a footnote in the instructions. Dry fabric pulls the foam straight into its capillaries, and there it doesn't work — it just vanishes. An evenly soaked roof is saturated: there's no more suction under the foam, so it stays on top where the dirt is.

Work with a soft, damp sponge, no pressure, in strips. Rinse the sponge out as you go, otherwise it holds on to the loosened grit and turns into a sanding block on a fabric with low abrasion resistance. The cleaner does the loosening; the sponge only has to lift it off.

For a single stain, the same rule applies on a small scale. Spray spot-on onto dry fabric and you end up with two problems: the stain and a tide mark around it, because the floated dirt is left behind at the drying edge. So wet the whole strip the stain sits in and work past the seam. The foam can go spot-on; the moisture has to cover a wide area.

Finally, rinse with clean water until you can't see any more foam forming. Dr. Wack names exactly this test in its own care tips, and there's a physical reason for it: surfactants are wetting agents. Whatever's left of them in the fabric lowers the surface tension of water and attracts moisture instead of repelling it. You'll notice it like this: a badly rinsed roof dries slower than before.

The brightener refreshes the colour, it doesn't re-dye

The colour-refreshing effect is real, and it has a clear limit: it's optical, coming from a brightener and from the grey haze being gone, not from pigment.

The formula contains a stilbene-based optical brightener, the same type of substance that makes white laundry look whiter. It settles on the fibre, absorbs invisible UV light and gives it back as visible blue. In practice, a tired-looking black looks rich again afterwards because the yellow cast is neutralised.

What it can't do is replace lost pigment. A roof that has faded on the sunny side after several summers will come up clean and even again, but not black again. That takes a pigmented soft top dye, and that's a different step with a different risk.

The second limit is mechanical and final. Where a stiff brush or a pressure washer held too close has roughed up the top layer or damaged a seam, no cleaner brings the texture back. Raised fibres scatter the light, the spot stays dull and grey and from then on picks up dirt faster. Dr. Wack's own care tips explicitly warn against pressure washers, car washes and stiff brushes.

The third limit is more a matter of context. There's no independent lab test of this cleaner: test institutes and car magazines have so far tested soft top proofers, not cleaners. So what's backed up here is what Dr. Wack states in its product information sheet, verifiable with the manufacturer in Baar-Ebenhausen. We'd rather say so than hint at a test win that doesn't exist for this product.

Cleaning alone keeps the roof clean, not dry

A freshly cleaned roof is open, absorbent and unprotected — and in exactly that state, the next step decides how long it stays clean.

Green film on a soft top isn't dirt that settles, it's something that grows. Algae and moss need just one thing for that: time with moisture. A roof that soaks up every shower and then needs two days to dry out gives them that time every single week. The cleaner gets the green film out. It doesn't shorten the drying time.

That's why Dr. Wack's instructions don't end with a full stop but with a fork in the road. If your roof is fabric, the Cabrio "Verdeck-Imprägnierer" fabric proofer goes on once it's dry, stopping it from soaking up water and so cutting drying time. If it's plastic or vinyl, the "Kunststoff-Tiefenpfleger" trim care is next, because soft PVC doesn't need water repellency but the plasticisers it loses over the years.

Skip the second step and you don't just lose the protection — you lose the cleaning work faster too. An unproofed roof soaks up the next rain, stays dark and damp for longer and in that time picks up dust, pollen and spores that cling to the wet fabric. The next green film starts the day you finish.

Who the can is worth it for: anyone who keeps their convertible outdoors or under trees, second cars with fabric tops that sit for long periods over winter, and anyone who wants to treat individual stains rather than foam the whole roof. If your convertible lives in a garage and you wipe the roof down once a year, an all-rounder from our fabric and upholstery care will get you just as far.

The point no manufacturer prints on the can: the can is also your test kit. Before pre-wetting, put a walnut-sized blob of foam on an inconspicuous spot of the still-dry roof. If it stands up as a white dome, the proofing is still alive. If it slumps into a dark patch within a few seconds, it's gone — and the second step isn't optional that day. Three seconds of effort, and you know before you start what you'll need afterwards.

How to use Dr. Wack A1 Cabrio "Verdeck-Reiniger"

From pre-wetting to the last trace of foam

Park the convertible in the shade and close the roof fully. Pre-wet it evenly with the hose until the fabric is dark all over, rinsing off the loose grit as you go. On a dry roof the foam soaks into the capillaries within seconds and stops working there. 2 minutes is enough.

Shake the can and lay the foam onto the dirty areas. Start at the seams, the lower panels and the shady side — that's where water sits longest and where the green film shows up first. On stubborn grime, leave the foam for 5 minutes; it won't run off the slope and keeps working the whole time.

Work with a soft, damp sponge without pressure in even strips. Rinse the sponge out after every strip so the loosened grit doesn't go back onto the fabric as an abrasive. Soft tops have low abrasion resistance, and one bit of grit costs you more there than a second round of foam.

Then rinse with clean water until you can't see any more foam forming, and go over it again if stains are still showing. Only judge the result the next day, once the roof has fully dried. Wet soft top fabric looks much darker than it does dry and hides exactly the edges you'd need to go back over.

Notes: Don't work in direct sun, or the foam dries on before it works. No pressure washer, no stiff brush, no car wash: Dr. Wack's own care tips explicitly advise against them, because the top layer roughens and the seams suffer. Faded areas come up clean but not back to colour — that takes a pigmented product. Once fully dry, fabric tops get the Cabrio "Verdeck-Imprägnierer" fabric proofer, plastic and vinyl tops the "Kunststoff-Tiefenpfleger" trim care. Store the can upright, somewhere cool and not in a hot car.