Can some of the experienced guys shed some light on the differences in the convertible tops available for the c4 ? mine is a '90, I've noticed that there is like 3 different materials available, whats the difference? My current top seems to be more of a cloth material as opposed to a vinyl, how water repellant is that and would it be a good thing to treat it with scotchguard? thanks.

 

Your top should have a visible tag on the inside mentioning brand and material. If not I'd drive by someplace that does higher ended tops and ask "first hand" for identification of the material and maintenance required.

First hand information I believe is the better choice than mine or anyone else here might offer up. There are differences!

 

All convertible tops were made from cloth (I think the material was called Sta-Fast??) except for the white convertible top. It was vinyl. The reasoning behind that was that a white cloth top would have been extremely difficult to keep clean.

When I had my '92 convertible, I never had any issues with water repellancy or leaking with the OEM top. The only cleaning material I uses was car wash soap and a soft brush.

Some people have had good luck with 303 Aerospace Protectant. They have a fabric water repellant that's supposed to work very well.

 

I've got an 86 with the black canvus top on it. It may have been in it's first rain earlier this month, came from N.M. so don't know what it experienced there. The top got wet, didn't repel the water and ironically had just gotten the 303 top kit in the mail the day before we'd left to go out of town where it got rained on.
I used the top cleaner on saturday and cleaned it up per instructions and left the car in the garage till sunday before doing the sealer. I put it in the sun for about an hour or two just to insure everything was fully dried out prior to treating.
I did it a little different, I have some 3 mil plastic leftover from an insulation project in the house. I cut some pieces out, released the top and slipped a piece between the top and the windshield, the top and the toneau cover and around the door windows so everything had a drop cloth setup. I also taped off the rear window and covered that also. The idea was cleanup would be easier, any overspray would be on the plastic, not the car.
I then coated the top per instructions and left it for another day that way to fully dry. when I finally pulled off all the plastic etc, I had to try it out and see how it worked. Water beaded up very nicely on the top so I call that a success.
I expect that's something I'll likely do every year or two. Don't know if it's really needed if it's beading water up properly, but seems to be cheap insurance.

 

An interesting video of the two most popular products:

 

The fabric tops should be completely waterproof with no protectant at all. The outer layer of Stayfast is a polyester, which will absorb water. It is bonded to a layer of rubber, which is waterproof. On the inside cloth is bonded to the rubber for appearance. If you do not want the polyester outer layer to absorb water when it rains or the car is washed then a protectant like Ragg Top or 303 can be used.

 

I'm not sure whether the top on mine is original or not after 28 years. Out of curiosity I look a light to mine and I don't see any kind of rubber layer bonded to the inside. Might be or might not, but it does shed water very nicely now.

PS I used to have a Spitfire Convertible, I can definitely tell you that top passed water till I dressed it, this top looks to be of the same material.

 

You cannot see the rubber layer from the inside. As I stated, there is a layer of cloth bonded to the rubber on the inside for appearance.

 

After 28 years your top is probably not the original one, if it was it would probably look pretty ragged. Any halfway decent upholstery shop should be able to point you in the right direction as far as what to use on the top.