Thats a good question...at the 2011 USVTA Southern Nationals, I went a got a 5mm rod to roll under the cars.....and I wasnt sure which way to do it...so we did it with the bodies on...and didnt count the front spoiler on the VTA bodies...
Ive done it without the bodies and found out that the bodies add alot of weight, which lowers the chassis when mounted...making some cars illegal
do the bodies on and just the chassis