Why won't the search engine allow me to choose a Nationwide search
radius? Currently it only allows me to go as far as 100 miles?
Thats as far as you can go out on pre-owned. 500 miles on new. I think CarGurus figured out that 95% of people are not going to travel more than 100 miles for a vehicle unless it is a specialty vehicle or something very rare. The most searched vehicles are Jeep Wranglers, Ford F150's, Toyota Camry, etc...which there are more than enough available within 100 miles of anyone's zip code.
thats bs. I always travel a good distance for the car I want
That's too bad, especially if you're looking for a classic car.