I have always found a way to put a tandem in even the smallest cars I've owned. It depends on the tandem as well as the car, and of course it depends on if anyone is getting in the car with you (my stoker has often had to travel in another car!). Wheels out, with one end of the bike on the passenger seat (headrest off, seat reclined a bit) the other end usually can be made to get in a hatch back. The hardest was when I had an S class Merc - but thankfully it was the long wheelbase version and it's a wide car so I got the tandem in somehow!