Since we're on it, we've found the best quality stuff, bar-none, at Wolfsburg West.
http://www.wolfsburgwest.com/ They will simply not sell anything they don't think is top notch, and much of their stuff is made by them in the USA. Yup. Dollar for dollar, the best.
We also like JBugs
http://www.jbugs.com/ and CIP1
http://www.cip1.com/.
Avoid Mid-America Motorworks. They sell low (Brazilian) and mid grade stuff at premium prices, often for as much or more than Wolfsburg West sells German stuff for. Don't be fooled by the pretty catalogs. The markups pay for their printing and postage.
That said, their car covers are top of the line and well priced for what you get, but that's where any value ends.
Avoid also JC Whitney. Cheap stuff and you get what you pay for.
Example: MAM marks up their TMI interior orders 30-90% higher than JBugs does. All they do is place your order to TMI for you.