I think it may have been answered already, but a flat tire will fit in the trunk depending on how much other stuff you have in there. My guess would be if you had a spare in there that was taking up space unless you had it jammed full of other stuff you could move things around to get the flat tire to fit if you took the spare out. I normally take 2 tires with me when I go to the autocross and they both fit in the trunk with it closed (I normally have 2 front wheels and tires, but one time I had a front and a rear and it still fit).

BTW this is in a SRT Coupe.

Thanks,

Michael