Tom chose not go out in the last race so he could help the 15 drivers under his tent change make the last minute change from dry tires to rain tires (they extended the 5 minute call to allow cars to get to the grid)
Tom's 1.6 of his was able to bump the bumper of the rental OPM VVT that I was driving, and pass it.
And that rental VVT is very strong (all my velocity time traces were as good as any of my personal car traces) and that same VVT finished 5th at the 2013 Runoffs at Road America in the hands of Joey Jordan.
As to its legality I would imagine that it is spot on, but as to its percentage of prep I would say its an 80% car. I doubt that Tom is throwing a championship budget at that rental car. IMHO there is probably more to be found in freeing bearings, brake drag, etc, stuff that would hurt a rental car reliability and rental customer experience, but would free up some time for the serious contender.