hehe ok I made a small picture up but witha lot of stuff 9 major fixes that would really improve the realistic feel of this car.
1.If this is a road going F355 which it seems to be the GTS model I dont think the Diffuser is neccesary hehe, looks cool but not realistic.
2.See how you made your round lights bend with the bezzel thats not correct, the F355s lights are snuggedinto the bezzel and they are straight.
3.See how your lip comes straight down (or so it appears) on the real car it curves down.
4.Everyone forgets this part lol but I always put it in, and remember it. should be a triangle type design in the trim. (I outlined it on the real picture)
5.Your exhaust pipes are to straight, and the tips should be angled a bit, and yours also look like they are pushing into the mesh.
6.Your LIcense plate holder seems to smooth its actually sharper than that.
7.On the pictures you will see those areas are not like door lines or hood lines they are more deeper and bigger, and in pictures they stand out to the eye more.
8.There is a line under the door ( panel line) I dont kno if you have it but I coudlnt see it.
9.Again same as number 7 more detailed.
Anyhow thats it from me, sorry I'm such a nitpick but Ive low poly modeld this car over 7 times and Ive come to know it pretty well. And oh number 10 PLEASE CHANGE THOSE RIMS lol put the proper 5 spokes on it will greatly improve it

hope this helps and I hope you make the changes I look forward to them if you do.