I'm apologise, please don't take it as spam.
Fist of all it's not my models and am i haven't any profit of it's sales (it is only altruism in a way of seaching model to convert for GTAV).
Unfortunately models not for free, but cost of each other don't get over 100$, anyway looks on it.
I'm just one of may be few people that whant that in GTAV will be more legendary mod for cars like
A) Porsche 356 speedster - i find not so expensive model with good quality
http://www.turbosquid.com/3d-models/3d-porsche-356a-356/818432
B) Porsche 911 Turbo (930) 1990 year - excelent model within an acceptable limit amount of polys for GTAV
http://www.turbosquid.com/3d-models/porsche-930-turbo-3d-3ds/821276
C) Porsche Boxster S 1996-2004 - the best i think cabriolet all over the world
http://www.turbosquid.com/3d-models/porsche-boxster-s-1996-3d-model/667731
D) Porsche 911 Turbo (993 body kit series)
http://www.turbosquid.com/3d-models/porsche-911-993-sport-3d-3ds/605550