Nature shots this time of year don't turn out nice unless the background is blanketed with snow or ice. This time of season, backgrounds such as industrial buildings or urban settings work best. I'm only looking to shoot a few cars this time of year due to the weather. Once it's nicer out, I can shoot 3-5 cars at a time. If there's more, there'll be less shots of each car, though. Manassas, Reston, or that general area has some good spots to shoot (ie top of parking garages) but you guys are more familiar with this area than I am since I only come down every 2-3 weeks.