Meguiar’s Convertible Top Cleaner

[True-Blue]

Thought it was worth a post on this product, as I had an excellent result with it yesterday.

My car is under 30k miles, but spent the last 12 months sat outside in the Valleys of Wales, before I rescued it. As a result, the roof was looking a bit sorry for itself, and there were a couple of large stains where someone had clearly tried & failed to clean something off previously.

I thought I’d sort it in no time with our Bissell Vet-vac which is great on carpets and upholstery, but this was a complete failure and although I sucked a lot of brown sludgy water out of the roof the stains were still very much present.

I’m not a Meguiar’s fan-boy, I do like some of their professional compounds but I think most of the stuff at Halfords level is ok but a bit pricey.

I wet the roof with a hose and then sprayed half of the roof with a healthy amount of this cleaner, I worked it in with a very soft brush for about 10 minutes then rinsed with copious amounts of water and repeated on the other side of the roof. I did this a second time and allowed to dry naturally.

I didn’t take any ‘before’ photo’s, but there was algae and stains aplenty... less so than before the previous attempt to wet-vac, but it was still a mess. This is how it looks this morning, I just need to decide whether to apply any weatherproofer or not?

 

[Crazy Harry]

NO. Doesn't need to be waterproof on the outside.

Its made in three layers. Porous outer; waterproof mid layer and 'nice' inner roof liner.

Great job on the roof by the way. I work a bit cheaper stiff brush and dry vacuum on a dry roof. Warm water with a cap of Miltons fluid in it (yes the nappy cleaning stuff) to kill the algae wet scrubbed in and rinsed off; then hot soapy water but each to their own!

 

[Hairyarse]

Looks like good results.

Although maybe not needed, I assume there's no issue with spraying a waterproofer on the outside of the skin?

 

[Ewazix]

Looks like good results.

Although maybe not needed, I assume there's no issue with spraying a waterproofer on the outside of the skin?

The hood's waterproof layer is under the porous top layer to allow even drying (even the best waterproofing solution breaks down). More importantly the waterproof layer on the oem hood is made of butyl rubber which can be damaged by solvents in some waterproofing liquids so isn't recommended by BMW (or any of the other big name makers that use the same hood manufacturer). Having said that lots of people do and I haven't heard of anybody's roof dissolving.

 

[Hairyarse]

Interesting to know, thanks for the info

 

[Ewazix]

Interesting to know, thanks for the info

No problem, it's one of those issues that's endlessly debated. I looked in to it in detail a few years ago after someone recommended using Fabsil on the roof. Now I'm a big fan of Fabsil on camping gear and waterproofs but knew that it contained some heavy solvents, a bit of research found that one of them is listed as damaging to Butyl rubber, the material used for the waterproof under-layer. So I tend to stick to BMW's recommendation not to waterproof despite huge beading looking so good!
https://z4-forum.com/forum/viewtopic.php?f=2&t=97037

 

[Hairyarse]

Blimey, could go horribly wrong if you weren't careful!! Thanks again, no waterproofing for me then!

 

[True-Blue]

A further endorsement from me for this product, picked up an Audi TTS last week which has lived outside for the last 3 years since being bought by the second owner.

Although comprehensively looked after from a mechanical perspective the car was parked on the street, and so it seems cleaning and pampering were a relatively low priority. It was also often under trees, so the roof was in a bit of a state with mould, sap and bird lime.

I had to clean the roof twice, once yesterday and again today, and one bottle was sufficient to do this. I was fearing the worst after the result of yesterday’s efforts, but the roof come up fantastically well after the second wash today. I’ve got a powerful ‘pet drier’ which is very similar to a number of detailing car/motorcycle driers but 50% of the price, so used it to dry the roof today rather than let it dry naturally.

I sure a decent APC would be just as good as the Meguiar’s soft top cleaner, but then you’d need to get your mix ratio correct, buy a sprayer bottle etc.

I definitely think this is much more effective than the autoglym equivalent, which I didn’t think was that great.

 

[The_Real_BruceWayne]

New member here and this is my first post!

I just purchased a 2004 Z4 2.2i that hasn't been getting the love it deserve.

The roof looks a bit dirty and I was actually looking for products to clean it. I'll post before and after pictures after I give it a clean with Meguiar's soft top cleaner!