.
Another term, "Stove-up".
I was a horse owner (Arabian)...30 years ago. Never again.
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Stove-up | Definition of stove-up by Merriam-Webster

suffering physical discomfort caused by injury, illness, exercise, or overwork : battered, worn-out horses … too old and stove-up for saddle work.

Rode hard and put away wet is how I have always heard it.

I never heard someone refer to a car that way, people maybe, but never a car

I have some advice to the OP.

Read some of our civilization's great literature. You have missed out on a lot.

Oh, and it is not so much the mane you need to brush out, it is the body of the horse. You use a comb that resembles a tiny version of the sort of saw it would take two guys to use to cut down a big tree. Small enough to fold over and hold in one hand, inch or two wide, with tiny teeth. You can use this to get a lot of the moisture off the horse. Cold wet and standing around is no way to be, don't recommend it for anyone.

Okay, lovely morning, done stretching before the walk, and the dog is getting anxious to be going, ciao

Speak for yourself, but I always put mine away wet.

In my mind the saying has three meanings depending on context:

1) The original horse one. Nobody wants to buy a horse that was continually abused by hard work and lack of proper care afterwards. (LEs and Don's references apply)

2) Hagard old cougars who look all used up and scary (as per other references in this thread)

3) A saying used with a sense of pride when applied to our manly man handling of our cars (not coddling) and the recognition of the thrashing our old 911s can take as per their deigned purpose (unlike some fragile other makes whose owners go to track days to have wine and cheese instead of real driving experiences).

1&2 are comments on condition. # 3 is term of endearment

I rarely just cruise in my car. My 911 is always driven hard and put away wet, (I drive the **** out of it and I'm proud of how I use it as intended, but in between it is always well cared for so that it will never be used up).

OTHER SAYINGS:
My 911 is my hot rod (If you disagree you are being pedantic)
My big 1300cc V-twin is my scooter (see how these saying work?)

Rode hard and put away wet is a 914 term. Entry level VW and most owners didn't have a garage and/or stored them outside when they ran.....and never started again.

Rust free, can't be turbo'd, never been wrecked.....ya right.

under 30 year old mellinial reporting.

knew the full phrase at its meaning.

owned horses when we were kids.

I have only ever heard it used on Pelican, and only referring to abused cars.
I'll be sure to look out for Equus taxonomy as I re-read Sophocles and Virgil this summer.

Owned horses, ergo, knows horse idioms.

Might I suggest the next time someone tries to help you when you ask a question, (assuming there is a next time), you leave the sarcasm out of your responses?
We all have different experiences. That doesn't make us better or worse.

Best
Les

I am a transplanted non-native English speaker. So the hardest part is learning idioms and local/regional expressions.

Thankfully, there is Google.

In Canada we have bathrooms.
I never knew what the song skip-to-the-loo was about until I visited England.

(someone must have been doing the green apple two-step when they wrote it.);)

Emily Litella.

Can't read the thread title without thinking of her.

I always heard the term, but thought it applied to the saddle....didn't realize it was the horse