All wheels off and seatposts out, quite possibly.
I think that would work, but could be tight – I can get my bike (27.5 hardtail) in vertically, resting on the handlebars and seat with the wheels off and the seat dropped. Could easily get another beside it, but there wouldn’t be room for much else once you put the wheels in. The boot floor sits lower than the seat backs which gives enough height for the forks if you put the handlebars at that end. Some models have a tray in that bit of boot which would reduce the headroom – maybe enough to stop the bikes fitting. I don’t know if they can be removed.
Decent little car, IMHO, but something slightly bigger would be a better bet.