But I never said any of this was a good idea, just answering how you can do it. Some car doors won’t close with a strap in there (my old Chrysler Lebaron for example, $800 of “Its technically driveable”), so me and a friend went in through the windows.
I had town car, all four doors would close just fine, but the station wagon only the front doors would close (so backseat meant crawling through the trunk, aka the fifth seat).