Hi...We're looking to buy a new/used car and have both a Britax Marathon and a new Britax Frontier Booster to try to fit into whatever car we get. Does anyone have these or similiar sized seats and a Kia Spectra or a Hyundai Sonata? I haven't even seen either car inside, so I don't know if I'm asking a silly question....like trying to fit 30 clowns into a VW Bug We might also look at the other Hyundai's....Azera, Elantra, Genesis. Thank you