Recomended Care for BMW Convertible Tops

1928 BMW Dixi 3/15

1928 BMW Dixi 3/15

Hello everybody!

BIMMERS! They are gorgeous and they have been around since 1928. The first one was called a Dixi. These first bimmers were powered by a motorcycle engine and weren’t much to look at for sure.




Holy Cow, we have certainly come a long way since the 1928 model!

2010 BMW M6 Convertible

2010 BMW M6 Convertible








Well, on to our main topic: BMW convertible tops are among the best that money can buy. They are a 3-ply composite consisting of an Acrylic outer layer, a polymer or rubber middle layer and a Polyester liner. The materials range in name from Twillfast 2 in earlier models to RPC Acoustic and Sonnenland in the current models. The Acoustic tops are very quiet and are a real work of art to be sure! But, no matter how well made a BMW convertible top is—they still need care and maintenance. They are not as carefree as the rest of the hard metal and plastic components of a car.


The soft top’s surface (acrylic) must be waterproofed and treated with serious UV protection or the sun will gradually destroy it! Without protection the Sun will definitely fade the cloth until it looks like your favorite golf shirt after 53 washings! Worse yet, without UV protection, the UV rays can actually peer through the fabric and start deteriorating the rubber liner!! Have you ever left an elastic on a window sill in the sun? Yep, it turns into brittle, useless crap! If that happens to your top—you get wet!


What can be done??


The best way to care for a cloth convertible soft top is with regular care, cleaning and maintenance. There are a “million” car care products out there but there are surprisingly few products for the care and maintenance of cloth soft tops like a BMW’s. BMWs were born in Europe and, in Europe, there is only ONE recommended product for caring for convertible tops. It is made by a company in the UK called Renovo. It is a safe, gentle but extremely effective line of products which are water-based and made specifically for expensive European cloth tops! The very first rule of soft top care is to  AVOID all products containing silicone or chemicals of any sort, and that is why Renovo is so strongly recommended as the only products to use! Not only are they completely safe for your soft top, they are completely safe for your car’s paint or clear coat and wipe off them easily if you get some on them. To care for you beautiful convertible’s gorgeous soft top, here’s the drill.


  1. Get a good scrub brush. Rub it across the back of your hand and if it doesn’t leave a welt or scratches – –  it is OK to use on your expensive top.
  2. Apply a good cleaner like Renovo Soft Top Canvas Cleaner according to instructions and scrub thoroughly. Rinse the foam and dirt off with a hose and let dry.
  3. If the top has faded and is unsatisfactory, you can now RE-DYE tops perfectly safely but that is a step that we will cover in future articles.
  4. After using a quality cleaner like Renovo you will need to Re-waterproof. You can use all those fancy “spray” can products which waste a lot and most contain chemicals, or you can use what they recommend in Europe—Renovo Ultra Proofer!


That water-proofer is the one I use on my Corvette regularily. It takes care of ALL your top’s needs.


  • UltraProofer lays down a very serious UV protectant or sunblock. Although you can’t compare it to sunscreen that we put on our skin, if you could, it would be huge, like SPF 700 or something !! This keeps the sun from fading your color out and it also prevents the sun from getting at your delicate polymer(rubber) liner!
  • It also provides an extremely effective mold and mildew inhibitor just in case you inadvertently store your top down when it’s be wet or damp! Wheew, have you ever smelled a moldy car???
  • It water-proofs your top like nothing you have ever seen! The water literally beads off just like off your freshly waxed hood!
  • Last but not least, it will seal your top’s surface so that dirt and grime can’t get a grip on your fabric. Picture a big deposit from some jerk seagull. Before—you would have to scrub like hell to get it off! With this stuff—since the surface is sealed, you can usually just spray it off with a hose!


All you have to do is clean and regularly maintain your top with Renovo and it should last you 20 or 30 years!

Oh, and by the way, be sure you absolutely stay out of caustic carwashes with your Bimmer! Not only do they use caustic cleaners, they fill your soft top with waxes and chemicals that help destroy it, and are hard to get out.

Use the Renovo products here, and you’re good for a couple or three decades. The kits are an especially good solution because they contain everything you need to follow the drill above. Kit A has Renovo Plastic Polish, too, so you can keep your plastic rear view window as transparent as the day it was born! You can read all about that, here.


Well, that’s it for now!  Keep coming back for more news, and in the meantime—


Let’s play cars!


-Soft Top Bobby