you may want to have a look at
The-Blueprints.com - 25990 blueprints online
not all drawings are in hi res but most cars have several drawings wich should allow you to extrapolate certain angles rather accurate... even the low res sketches can be of use if you import them into a vector drawing softwae (like the free package inkscape) and draw a curve anong the pixeled edges.... wich you can tha scale and overlay on a different drawing