I mostly use the M18 0880
I recently got the 0910 6-gallon and for me it revolutionized larger shop vac use mostly because of the lack of a cord. Much like OP I hated the cord on my old Shop Vac.
I totally realize it's a First World problem but cords just drive me insane. I literally get anxious and agitated.....so maybe I should be medicated???
The 0910 also has a lot of smart features like a nice, long, flexible hose with good hose storage. Milwaukee claims the hose can be rolled over and forced flat and not suffer damage, although I'm skeptical.
It runs a surprisingly long time on a 12.0 and power is good. The casters are quality and roll easily, so you're not fighting it while trying to position it.
Finally, with a simple foot pedal it unclips from the rolling base so you can carry it around. Losing the base also significantly decreases the weight, making it easier to carry.
Apparently I'm an info-mercial for Milwaukee's newer shop vacs (there's also a 9 gal version but the 6 gal is plenty for me) but it really made me NOT hate shop vacs. Still, you may need to find the attachment of your choice for cars, depending upon carpet or upholstery types.