Ducati Monster Orthos
The first thing you need when modeling something in 3D (or drawing in perspective from plans) is a good set of orthographics — top, front and side views. Start your search at The-Blueprints.com.
There’s a wide variety of cars, trucks, planes, trains, helicopters, motorcycles, ships and even sci-fi vehicles. Quality and size differ from one to the next, but you’re bound to find something interesting to model.
X Wing Orthos
Nice! I see they have Vector downloads too, that could be useful.