Once upon a time people drove volkswagens, and when poor surfers could afford nothing but used volkswagens they found they could transport even their longboards on roof racks. It wasn't a problem. Even the overhang wasn't a problem unless your tie downs were a problem.
Shorter boards were stuck diagonally inside, no need for passengers
Hatchback small cars were invented to help the surfer particularly in the UK, keep both the board and the fingers warm ( frosty fingers mean problem tie downs). longboards can fit in some cars, but hanging them out an open hatch is not a good idea each bump means cumulative dings and the open hatch wafts Carbon monoxide in through the hatch gap,.
Not good for the health.
Also is your long board a long board or a short long board? The car dimensions are a little over 4 metres and some guys have found taking out the back seats in a sedan adds the boot space to the board carrying capacity.
I short I don't really know but I'd take my board along and see.

I've taken up troll hunting just for fun, instead of a rifle I'll just use a pun! 冲浪爷爷