use style > Trace sketch > insert front, top, right view of a car you want (usual .jpg etc format).
trace sketch is great if you have blueprints.
surface design is hard in any software but if you willing to give some time i.m sure you will achieve your goal
Depends on how much of an understanding you have with ISDX tool in proe; free curves, tangencies and how to acheive the continuity. If you have played around ISDX then let me know, it'll be easier to walk you through. Also, which version of Proe do you have?