Oh, now, y’all!
The OP, (bless their heart) probably isn’t familiar with the joys of renting a car…it IS kind of hard wrapping your mind around the concept that Dodge Neons are considered luxury cruisers and that rental agencies are twitchier about legal matters than the most OCD small-print lawyer in the country.
Compact in rental land means stripped to the flippin bone, and always has. I showed up at San Jose to pick up a compact and it was some 3 cylinder manual steering under powered POS. I DID upgrade out of that one, rather than never hit highway speeds on the 101. Just go to Orbitz or other online sites and CLICK on the cars that they show for compact - you can see what you will get.
When I travel I insist on mid-size with my employers (I have even brought it up during negotiations once for a position that had 70% travel). I want power and size to protect me when driving around strange cities.
If I was getting a car for 17 dollars a day anything above a Yugo would be a bonus- seriously.
I bought my Ford Focus in 2005, an exhaustive online inventory search showed that there were a number of Foci on the dealer lots with the base trim, which included no power windows, no power locks, and no cruise control. (I had to go to another state to find one with side airbags.) So those hand-cranked little guys must be out there on the road somewhere.
Anyhow, doesn’t seem like a big surprise that a company named Thrifty would build it’s fleet with no-frills cars.
You do know the rental agent makes a commission on the upgrade, don’t you?
A smart car rental manager keeps exactly one of the stripped down models on the lot at all times. He or she will show it to people who reserved it, knowing that there is an excellent chance they’ll pay the upgrade fee.
If you challenge them to a game of chicken, most likely you’ll receive a complimentary upgrade because the stripped down model “needs an oil change” or something like that.
I hope you had them check over the car for damage before you turned the keys over. Rental companies are notorious for billing you after the fact for phantom damage to cars.
Personally, I quite like Thrifty. I rented a compact from them in LA in 2006 and they gave me a free upgrade to a Dodge Caliber. Nice car, although the windshield seemed very small. Then in 2007 I rented a compact from them in Denver and they gave me a free upgrade to a PT Cruiser. With satellite radio. 
In both cases I never said a thing to them besides asking for my rental. They just asked me if I wanted a free upgrade to a large car and I said yes. I will use them again.
My wife and I usually rent from Budget - different name, but same idea - and their fleet is hardly no-frills.
The one point I think is semi-implicit in the OP, although the OP didn’t make it directly, is that rental cars so routinely have all the standard gizmos plus some of the newer ones, that one develops the impression that all rental cars have 'em, so you don’t have to specify the remote door locks, the cruise control, the CD player, etc. Then one day you pick up your rental, and it’s the kissing cousin of the one the OP got. It can come as a bit of a surprise. But still, no big deal.
This I believe. And my WAG is that if someone says, “screw it, I’m not paying extra for the upgrade,” then any customers later that day who rent at the cheapest price get a free upgrade.
I can’t believe you would think it OK to just leave your car parked in their lot. Their customer parking spaces are to use while you are making a transaction only. They are not in the long term parking business, nor should they be expected to (at least free of charge) and yes “simply” leaving your personal car there does expose them to some liability - I assume you would hold them responsible if your vehicle was somehow run into while you were away.
Sounds to me like Thrifty provided the exact service they were being paid to deliver.
I’d agree, except other rental agencies at the same airport don’t have this same policy.
What airport would that be?
Actually, you usually get, “This is your lucky day. That car is actually scheduled for its service so I’m going to go ahead and give you another car…” The rental agent will then leave the stripped down version there for the next sucker.
BTW, I did work in the rental car business for several years in the 1990s.
I can see how that would be the more profitable approach.
What’s surprising is that they didn’t use that approach on the OP, but made him take the stripped-down model. Maybe it was late in the day. Or maybe he pissed them off enough for them to stick him with it.
And I appreciate the insights you’ve gleaned from your experience. 
I’ve also had the pleasure of being given a free upgrade after being offered one for cash and declining. However, I was not informed of this until I located my car on the lot, so they didn’t even tell me I was lucky to have the upgrade. I was a bit miffed that it got worse mileage than the one I rented but the satellite radio was a plus (and it had a 14+ gallon tank so I only refilled it once.)
The next time renting at that airport (not necessarily the same company,) I was asked if I wanted to pre-buy my gasoline, which is usually a horrible ripoff, but this was a couple summers ago when gas spiked like 50 cents in a couple weeks. So the quoted prepay price was less than the street price, so I accepted.
When my car was stolen, the rental insurance paid for a compact car for 30 days through Enterprise. I called and explained the situation and reserved a compact.
When I got there, they had muffed the reservation (or so they said) and so gave me a PT Cruiser (mid-size with Sirius radio) for the same price.
Then when someone threw a rock through the TP’s window, they were obliged to give me another car for the same price, but all they had available was a 2008 Ford Mustang. I drove it for a week. 
What’s a “cargo cover”?
Perhaps, one of these.
Basically, yeah. When you have a hatchback (I have a PT Cruiser, which technically is one, sort of), they give you a carpet-covered (or plastic) cover. It’s basically a shelf that’ll hide your crap from sight. Useful if you need to have your laptop or a bunch of stuff in your car.
