I recently tried relayrides.com which is AirBnB for cars. Mine actually picked me up from the airport then back to his place for the handoff. I got a big truck (I can’t remember the exact model, but it was F150ish in size) for $25/day. A bit used and beat up (like borrowing a friends truck), but seems to get the job done if you jst need a cheap car to get from A to B.
I’ve tried the super discount car rentals but the service was so bad and nothing was covered so I had to pay a bunch of extra fees, that going a brand name (Avis/Budget/Hertz) would have actually been more economical.