Ahh, got it. Actually my situation was far more convoluted than that. Which is why I didn’t include the details. Since you asked …
My fancy-pants sports car had a non-repairable tire failure on the freeway 700 miles from home. I limped into the nearest tire store at noon on Saturday. A store that would close at 5pm and reopen on Tuesday. I hadda get tires installed in the next 5 hours or spend an unplanned weekend in some random Nowheresville.
Their store didn’t have the rather esoteric tires I needed. Luckily a sister store 30 miles away did. But they didn’t have a runner to go get the tires today; they’d already done their daily run. Meantime, I’m trapped here at the tire store on foot. What to do? What to do?
Aha! A Home Depot is right across the highway. They rent trucks. I’ll trot over there, rent a pickup, drive the 30 miles, pick up my new tires, drive back, get back by 3:30 and that gives them 90 minutes to get the job done before closing time. Yes!!
But when I get to HD it turns out they had already rented all their pickups (remember it’s Saturday afternoon; of course they’re all rented out). I had no slack time to wait for a pickup to maybe get back in time. The 16’ Ryder truck was all they had right now.
So off we went across town in the Ryder to pick up two car tires. Wide, low profile, expensive tires, but just 2 of them. It looked pretty silly rolling the door down on that cavernous empty space loaded with two whole tires.
The total cost to deliver my two tires across town was a bit silly. But far less than the alternative: 2 nights in the local Holiday Inn & 6 meals times 2 people.
They got us back on the road by 4:15 with 45 minutes to spare. Whew.
And now you know … the rest of the story. 
And FTR, even if my car had been drivable I could not have carried even one tire on board. Too bulky.