All modern cars have structural rigidity and crushability built in, if you remove the spare tire you remove some of your protection either in a rear end crash on the street or track. This has been discussed many times here and searching will reveal the comments. The Viper days requirement shoud be a solid heads up for anyone doubting the argument. As to the argument about changing your wheel..Where you gonna put the damaged tire and wheel? That's right, back where the spare was, now you've probably lost a little rigidity as the tire is flat, but you still have a lot. And what the tire/wheel is supposed to do is absorb energy so that the car or gaurd rail or whatever does not intrude into the passenger cell Anybody know what that big wall is behind you when you sit in the car? It's the gas tank. Would you like to stop a rear end collision from reaching that or would you like it to rupture all over you. Think about it. Having said all that, I just went to the garage and got the owners manual for a 2000GTS out of same. NADA..nothing. Do I seem to remember that it is structural for an RT10 only because of the lack of rigidity due to the Targa top? I dunno. I do know that I did a magnificent Dukes of Hazzard offroad leap a few years ago in a brand new 90 LS400 while avoiding an idiot who pulled right in front of me. I missed her thereby saving her life and the car sacrificed itself for me, saving me with all the safety stuff that was pretty new at the time. I still wound up with a broken vertabrae. Ever since then I pay attention to anything that can help my survivability. If Viper days says it's safer, mine stays in. On another note to those of you modifying the cargo area in a GTS, if you block those vents off in the sides you can blow your rear window out at high speed, those vents are to get rid of high air pressures inside the car at speed. Again this can be doucumented by searching here.