Well, to make this legit, let's just try to figure out what your possible times could be.
Secondly, let it be known that each car is only as fast as it's driver's ability.
That being said:
A stock celica GTS (auto), I beleive runs in the area of 15.6 - 15.9 (assuming it's being driven by a professional). It being an automatic might help him a little. A lot of people don't really understand lift or know how to fully take advantage of it. A cold air intake might shave off a couple tenths of a second. The shot of NOS I'm not 100% sure about, but my prediction is it's capable of a mid to high 14 second run. No less.
A stock 2nd gen MR2 turbo is capable of a 14.7 stock (again, professional driver). Though, your car will be a NA with a 2nd gen 3sgte swap. Being a NA will make it slightly lighter, possibly making it a tenth of a second or two quicker. Now, cap off your boost sensor, spend $50 for the Two's R Us MBC, turn it up to 14-15psi and you're more than capable of a low 14, maybe even high 13 second run.
This is all derived from my limited knowledge, and should be taken as only a guess, and nothing more. What a car is capable of and what the driver can make it do are 2 totally different things. I've seen brand new Evo's and STi's running high 14's only because the driver had no idea what he was doing.
Practice makes perfect, you know how the cliche goes.

and good luck! Make sure to post your times on the registry when it's all said and done.
Oh, and BTW, try to stay away from posting car vs. car racing threads. I know this board is pretty lenient, but some might misinterpret it for a street racing thread, which isn't looked too highly upon. So, keep the racing at the track, and all is good.
Good luck again!