Honestly, cleaning and protecting the soft top is not rocket science. Modern fabric tops are very well made and don't age as badly as older technology. Frequent hosing off is best. Raggtopp is good stuff, but you can clean and protect for less - just use a low alcohol, low detergent interior cleaner and a brush to clean the top, then follow with fabric protector, like Scotchgard. Don't ever use "car wash" to clean it. I use Griot's interior cleaner. It seems to do a good job and it's inexpensive.
Raggtop's waterproofing compound comes in a spray can and looks like Scotchguard after it's applied. It leaves a slightly shiny finish on the material. A big difference is that Raggtop carries a seal of approval from Haartz, I think the source of our top material. An annual application should be fine if your car is normally garaged.
I too would like to know the best product to clean and protect the convertible top. The difference is my car is never in a garage because its my daily driver.
Also in the winter i used a scrubber to take the snow off my convertible top, and it left a few lines on the top and now i dont know how to get rid of them? I also went to the dealer and asked for any cleaner or top protector and they sold me this spray and it actually says "Not for CLK Cabriolet" lol i even told the dealer its for my CLK and they still sold it to me? lol
You probably won't be able to get ride of the scratch marks. Cleaning and following with a protector may help hide them some, but they will keep showing up. My top has marks on it where it rubs against itself when folded in the trunk. There's not much that can be done, so I just put up with it. The dealer is supposed to sell Raggtopp as the cleaner. I am not sure why they gave you something "not for CLK". That's bizarre, but dealer parts guys aren't always the most knowledgeable and their computer system isn't the best - it can be confusing if you don't know all the intricacies of using it.
So, I think we can summarize that there are three basic choices here: Raggtopp, Griot's or "make your own". All three have the same two components, which are a cleaner and a protector. The cleaner is basically a low-sudsing fabric/surface cleaner. The protector is a chemical fabric coating like Scotchgard. Whatever option you choose, you are mainly just treating the top for looks. The real waterproofing layer that does all the work sits below the fabric you see. Of course keeping the top clean and free of harsh chemicals, and protecting the fabric surface with a repellent can help keep the water barrier safe.
No cleaner is going to repair scratches, abrasion marks, or fading, but they can help mask it a bit. The protector will darken the fabric a little and give it a nice sheen, helping it look "newer", until it wears off, of course. Some people will suggest using a horse or boar's hair brush, but a good old fashioned nylon bristle brush works just as well. One word of advice - mark the brush as being ONLY for the cabriolet top. The last thing you want is for the spouse or kids to grab your brush and use it to clean dirty soccer shoes, the dog, the toilet or the barbecue grill.
I actually tried something different on my top last fall - I got a bottle of Granger's tent cleaner and protectant. I used it and I really liked the results. The cleaner seemed to be just a typical mild fabric cleaner like Raggtop or Griot's. The protectant, however, is different. It contains some silicon compounds that actually waterproof the canvas. Of course we don't rely on the outer fabric to be waterproof - it's bonded to a waterproof layer underneath, but still, if you can waterproof the fabric, it should stay cleaner. My top now beads water like a new-born baby's butt coated with Vaseline. The only problem - and it's a minor one - is that the water that runs off the top's drain channels leaves streak marks on the glass. Otherwise, it might be a cheaper ($15 for the kit) and better waterproofing solution worth a try.
EDIT: Oh, and after almost 6 months, many rains and a dozen washings with Griot's fabric cleaner, it still beads like a baby's butt.
I use a solution of Woolite Extra Dark Care (that protects the black color of my top) and water, and then use a gentle fabric brush. I have luck removing nasty bird droppings and pollen when they tragically appear on my tops, and yet maintain the black color of my tops and prevent rapid color fading.