Good God people! Please spellcheck before posting! It's so hard to keep up with the post when words are mangled! A few oopses here or there are normal, but man...
It seems that most people are missing what Richard is trying to do! Don't "soup" up your car just for this race, but let's get out there and see where everyone comes across the checkered line. People are still going to buy their "favorite" chassis based on whatever is important to them: authenticity, cost, performance, comfort, etc., etc. I don't see any negatives from that standpoint.
This seems like a very healthy competition that with the right media attention, could bring some very positive exposure to this industry. Just imagine the stoplight: cobra, SUV, cobra, cobra, mini-cooper, cobra, pickup truck, cobra...
There can be a debate about specific details forever, but the original suggestion is the best: common driver (skilled), same engine for all (even though the mfr might offer another as "standard"), same track, some warmup time then a few timed laps. This should provide the most accurate "car only" test.
In the words of celebrity deathmatch: "Let's get it on!"