should i sell my 03 cl-s fully loaded and modded for a 05 coupe?

 

Hate to say it... but if you have to ask, the answer is probably no.

 

why's that, just wanted some opinions
how is the aftermarket for the car, i hope it is better than the cl

 

My answer is YES! If your cls is fully modded w/6-speed, it is probably around the same speed as the new G. Chances are though, your cls will never ever handle as well as the G. A 60/40 bias is never a good attribute for superior handling and that is where the G shines. If you can afford it, its a worthy investment in the fun factor.

04 Coupe Auto/DG/Prem/Nav/Perf

 

Depends on what it is you're looking for. I'm not aware how large the aftermarket is for the CL-S, but the G35c is decent and many mods for the 350Z will work on the G35c (engine/suspension). Given that the CL no longer exists, if you want to continue modding, the G35c would be a good choice.