Ditto on the above. Their products are outstanding. I bought their Rubber/Vinyl Cleaner and their Rubber Dressing. I used the Cleaner on my '85 300ZX Turbo's rear wing, which I thought was trashed; it cleaned it right up, and the Rubber Dressing made it look brand new. The products are expensive, but I feel that it's worth it given the results I've had.
Do I like Griot's Garage? You betcha. I was so impressed with the job their products did on my Z that I called them. The secretary told me Richard Griot was busy but that she'd take my number and have him call me back. I thought, "Yeah yeah", but I gave her my number anyway. I'll be darned if he didn't call me back two hours later. We talked for about an hour about everything from his products to cars. Very nice guy, very knowledgeable and very helpful.
I've been a customer since 1998.