While I'm not Anti-XV, I've bought the stiffening kit,I don't see much on their site I'm impressed with. They seem to perpetually out of stock on most items, the GM belt buckles are a huge turn off, and the prices are absolutely rediculous. It's obvious they desire to be a low volume high dollar operation. That's fine with me because it is a free market economy. I prefer to give my money to someone who is more competitive with their pricesand has much better customer service.
The products they carry can often be found at better prices. Hothckis suspension systems are a much better value than the XV OEM derived suspension. THe seatbelts, as shown earlier in this thread, can be found elsewhere and without the 80'S GM buckles.
They do have some top notch products and for those they can set their prices however they want to and your not going to find it elsewhere.
As for the original complaint about gas tanks, there are cheaper and much better products out there. There are vendors that have been building tanks for decades. Also, I would only go with a company that uses top notch pumps like the Aeromotive A1000 because an in tank pump has to be proven.