Seriously, I have not had a breakdown in 20 years so I don’t know how it works . I have the routine maintenance done, oil change, a/c filters, oil filters etc at one of those drive in places and trade for a new Tahoe ever 70,000 miles. I never have to go to the dealership except to get another new one every 3 to 4 years. It works for me.
My recommendation would be to have an extra set of keys, and keep them in your purse. Here’s why.
With the older vintage stuff, you can tell when somethings not right. Some odd noise, a lack of power, soft brakes. Something. The older stuff usually doesn’t just die when you’re tooling down the freeway. If you know your rig, you usually have plenty of warning.
The newer stuff also usually doesn’t just die on the freeway. But you have a different problem. If you shut it off, and somethings wrong, lotta times, it just AIN’T GONNA START.
You’ll get a couple pretty lights on the dash telling you something cryptic about what’s not going on, after that... nothing.
So if you are off the beaten path, and suspect there is something wrong with your vehicle, and HAVE to stop for a few minutes, you are way better off just leaving it running and lock it. If you shut er down, then all bets are off!