We er... struggled, to get the hutches in the car lol. 5 foot long planks of wood don't fit in cars too well unfortunately. We were stubborn so managed it in the end, were just in less than perfect seating positions for the drive back. If they were any bigger we'd probably have failed to get them in the car to be honest.
80cm by 50cm cages sit in the boot, 100cm by 50cm cages get squished onto the back seat. Oh or we put the back seats down and can transport two Alexanders at once then
I swear when we eventually move I'm just going to hire a van for a day, still dismantle the hutches and stuff but hire a van. It'd save us so many trips between the two places.