I can get everything I want in a new BMW 328i… or I can get everything I want in the BMW X5 that she wants. 
A chauffeur.
How about this little darling? Yeah, sorry about the Spanish. We can’t sell 'em in the States.
I did a similar thread last year (except it was about real life cars). There are plenty of features out there that most folk think only exist in Sci Fi movies. I think I’ll go out and test some more cars this week 
I could do that in my first car, a 1965 Land Rover. And I can do it with the bottom of the seat in one of my current cars, a 1974 Rolls Royce Silver Shadow.
No worries about the Spanish. That’s not a bad rig but considerably more truckish than I had in mind. I’d be happy with front wheel drive and half the bed length.
Thanks anyway.
Like the Peugeot 308cc
Or Ford Focus Coupe Cabriolet
Or Renault Megane Coupe Cabriolet
Or Vauxhall Astra Twin Top
Or BMW Z4
Or Mercedes SL
My Volvo does that as do many cars.
Or the originator, the Merc SLK.
Free.
Mine would permanently say “No, no, don’t signal. I’m keen to guess.”
Low price
Infinite mileage
Auto pilot with mixed drink dispenser
Stealth technology
Cooled seats
I’d like the front doors to slide forward, like a typical van door. Easy ingress/egress, no door dings, no taking out in-attentive cyclists. We would take up much less space like that!
As a cop, I always wanted a button that would simultaneously jam the car to a hard stop, slide the doors forward (open), and release the seat belt so I could get a 1-2 second jump on the fugitive we were chasing when they decided to bail.
And the seats should rotate, too!
And of course, cameras covering 360 degrees. Because stuffhappens.
To me, anyway.
I want my car to fly.
A remote temporary immobilizer so that I can shut down everybody that goes 64 in the left lane and won’t move over. They can resume blocking everybody once I’m past them.
No beepers or buzzers inside. I have no idea what they are for. I guess they are to remind us that cars are generally dangerous?
Multiple 12 V receptacles on and above the dashboard, and ready-made passageways through the roof columns for fishing cables. Cars are always 1 or 2 inventions behind electronics and will never, ever, ever catch up.
Roof rack made out of 80/20 aluminum extrusions.
Brake and clutch pedals are equal size squares, so you can keep rotating and trading the rubber treads and they wear evenly.
Carpet and upholstery that come all the way out and can be machine washed.
That’s an interesting thing to want; has excessive pedal wear been a problem for you? Are you a race car driver? 
I hate noisy vehicles. I am the opposite of those people who put loud pipes on their trucks and bikes. Therefore, I want my car to be electric, and therefore quiet, but with improved battery and charging technology that goves it range and recharge time equivalent to a gasoline car’s range and fillup time.
I have a 1995 Escort with 138k, and my clutch cover had worn away.
A car that morphs into a pizza and a six-pack at 8PM, a pretty woman at 9 PM then a cigarette at 10PM.