Will 2 Britax carseats fit into Kia or Hyundai?

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:)

I have a Britax Marathon in our '04 Sonata and it's great! I'm not familiar with the Frontier, but there's definitely room for another car seat back there (we plan to have one some day.)

We LOVE our Sonata. No regrets whatsoever about buying it.