We reserved a full size and wanted the Impala for our one carseat. Impala was available and very roomy, however we had difficulty with the Latch system on the Impala.
Couldn't get the Latch from the carseat to hook to the Latch in the Impala. It seemed like it was sideways and had a kink in it. We ended up having to take a Camry instead. Carseat installation was very quick in the Camry.
Just wanted to give you a heads up in case you were planning to use Latch and are used to an easy install on your own car.