Can you get a prescription windshield for your car?

No. The closest you can get is plain (untinted, unshaded), tinted, shaded, tinted and shaded.

I’m sure if you were very very rich you could.

No. That’s not how glasses work.

It would be a little impractical. I would suggest a giant pair of glasses with legs that fit over the wing mirrors.

Yes.
It’s called a chauffeur.

There’s an old joke about that.

A guy is hitchhiking through Texas and a mammoth Cadillac pulls up -it’s like a cartoon of a wealthy oil man’s car, with steer horns on the grill and when the driver hits the horn it plays The Yellow Rose of Texas. The hitchiker climbs in and notices driver has $1,0000 cowboy boots and a hat that might cost half that.

They head down the highway at about 90 miles an hour. The hithchiker notices a pair of really thick Mr. Magoo, Coke bottle glasses on the dash, and asks nervously, “should you be wearing those glasses?’

“Nah, boy, no need. I got me a pree-scription windshield!”

Yes. This is absolutely possible. But, the windshield wipers would need to be installed on your eyeglasses.

Yes. But the car might catch fire.

Everybody’s eyesight changes over the years, some people more frequently than others. It could get REALLY REALLY expensive to have to change car windshields every time you eye prescription changes.

And it would be impossible to lie comfortably in bed reading.. Unless you had a removable windshield and even then, it’s still too heavy to carry around :)

It’s a lot easier to just wear glasses when driving :)