They're not too bad on the pax side, as the footwell is big enough to have that seat quite far forward to allow someone to sit behind. Driver seat is a no-no unless you're a midget, but the biggest trouble is the headroom: If you're an adult, there simply isn't enough for anything beyond the shortest journey. S'okay if you're a kid, but otherwise you're left crouching down which really isn't comfortable.
It's why I removed them out of mine, they're pointless and I'm an anti-social git anyway