Cool part of a bike's rim and swing-arm.. you just take the axle bolt out, and drop the rim/tire.
Bike rims will accept car tires.
the only thing that really needs to be adressed is whether the bike's swing arm will handle the torsional/lateral loads of a small <1 ton car, even with the worst drivers in terms of cornering.
I'm sure you could use a cheap LP tire, since I can get Wanli 18" tires for less than most standard passenger sizes.. and they still last for up to 30,000 miles.
Tire prices for 16/17/18" semi-performance (street) tires
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