A giant chunk of why Lower Half Gen X and on aren't having as much sex is because we stopped having those rolling sex pods of cars.
Seriously, a giant chunk of the 40s through 70s got laid in what amounted to a bed with an outboard motor.
Look, I've tried to fuck in a Corolla and a Dodge Charger, and the Charger is at least plausible. The Corolla just isn't big enough. Fuckable cars aren't affordable anymore.
The minivan: Not just for soccer moms.