It is not likely that Bed Bugs Live in Cars, unless someone is sleeping in the car regularly. Bed Bugs stay close to their hosts which are people.
What attracts bed bugs to people is the carbon dioxide which we breath and our warmth. Without those two factors, bed bugs do not hang around. Bed bugs do not fly and they do not jump; infact bed bugs will not even climb on you. They stay on the sheets or blankets and bite you from there; any skin touching the sheets can get bit.
Bed bugs love to hide in cluttered and dark areas such as closets.
If you think there are Bugs in your car, it is more probable that the bugs are fleas because bed bugs can not live far from the host without a blood meal. Again, if a person is sleeping in the car, then bed bugs CAN indeed live in cars, but it is not probable if you are not sleeping in your car.