With our car, my bike fits in the boot with the front wheel off, and we still have the normal 5 seats
And any stuff can be packed around the bike aswell, or on the back seats.
No good if you have more then one bike, but for one bike it works. Its not an estate car we have either.
One of the main things that change the fuel economy for my dad(not so much with my brothers little 106) is just having the roof rack on makes the fuel economy go down enough that we take it off and put it on when we need it.
My bike goes into the caravan when we travel anywhere, so its even better