My 2008 Yaris and 2013 Elantra both have the 20 seconds to use the windows after the key is out feature. Well, not the Elantra, it’s more like 20 seconds after you push the start/stop button.
I’ve had a number of occasions where I had the power off but wanted to operate the windows. And what happens if you ever have an accident, especially a submersion, where opening the windows is your only means of egress?
Grill mounted, 1920’s style death ray.
One neat trick with Volkwagens: if you put the key in the door lock, turning the key and holding it one direction rolls the windows down and turning the other direction rolls them up. I always thought that was a super-neat feature, although now most newer Volkswagens don’t have it because they’re going away from physical keys altogether.
Urinal
I would have be amazed if it was actually 20 seconds. Lucky guess and all that.
I quick search on Yaris suggests that it’s the driver’s side window only and for 45 seconds or until driver or passenger door is open. Which is a pretty good choice, too.
Bill Harrah had a Jeep Wagoneer with a Ferrari V-12 under the hood. I’d do the same with my 63 Ford Unibody.
I’d like a 6-speed manual in my big BMW. All-wheel drive in the medium BMW. New Recaro seats in the little BMW. More power or better sound systems in the rest. Except the Jeep. I simply want reliability.
Jesus Christ himself couldn’t pull that last one off!
Four 120-degree ‘dash-cams’ somehow* mounted above each of my turn-signals so I’d have video evidence for the cops when people on the highway are zipping around and cutting me off (when I’m already exceeding the speed limit).
Or a pair of those 24" long air horns that the interstate truckers mount on the tops of their cabs, somehow* mounted above my wheels. I’d use it to let people know I’m there when they’re changing lanes without turning to see if it’s actually safe to do so.
—G!
*I’m on a motorcycle; the mounting has to be resistant to high winds and harsh weather. Plus it can’t interfere with the seating or handling.
It’s amazing how many weapons platforms would be mounted on dopers vehicles. Why they decide on this over instant teleportation to their destination just goes to prove why we are not yet ready to be accepted in to the interstellar community and answers the question as to why they have not contacted us. With this I wouldn’t want to know you either.
Ventilated seats - now in Hawaii so heated anything is about useless. Heads-up display of speed and instantaneous gas mileage - teaches me to go lighter on the right foot. Window tint that automatically varies with solar exposure and vehicle condition - really dark when parked outside, clear in the evening and at night (in the future, can autodim the idiot with brights in the on-coming lane).
Into the absurd - Message boards to display correctly to the drivers around you how they could improve their driving and attention span - kind of an auto-threat response system.
Would you rather have that or the Mr. Fusion flight package?
They have heated steering wheels now? Gosh.
I’m having a hard time deciding between turn signals on my side mirrors, a tire pressure system that reads out on the dash to let me know if the tires are low, and an AUX jack to plug my Sansa or my tablet into the car stereo system. The last two are now standard on the Forester trim line I bought back in 2004/5, but you have to go up a trim line to get those turn signals. I wish everyone had those. Designers keep doing things with turn signals that make them hard for me to see, especially if they have their headlights on; I often have to wait until someone is actually turning to be sure that they are.
Although given the way some people drive, that may be a good thing. it’s no fun seeing a turn signal, figuring you can go, and then discovering the oncoming car has been turning left for the last 20 miles.
As for ordnance on the car, y’all might enjoy a short story by Alan Dean Foster called Why Johnny Can’t Speed.
I think I’d like the hatch to lift by itself when I push the appropriate button on the remote. I often have both hands full, and it would be an improvement.
Unless that google self-driving car thing is available. Then that.
Better MPG.
Hand controls on the steering wheel..
OK, it isn’t “common” like a new stereo or air conditioning or whatever, but there are so many times where my driving leg is just too fatigued (at the end of an hour in stop and go traffic that knee is SCREAMING). Heck, the hands are on the wheel anyway, why not take advantage of it.
A more common option, and one I may well get on my next car, is a backup camera system. We rented a minivan a couple years ago which happened to have that, and it was great!
I really want a sunroof, it wasn’t an option on my Mazda. It at least has plenty of other goodies that I like.
Which car? 
On my daily driver, I’d like to add cruise control because they forgot to add it when they ordered it from the factory.
This long and no asking for a hardtop convertible?
I want a convertible so badly, but for those rainy (and sometimes snowy/icy) days I don’t want the heat loss from a soft-top, so I want a hardtop SO badly.
I use my moonroof constantly and love it, I just want more cuz I love the sun and love being outside.
Heated steering wheel for sure. And I wish my tire pressure sensors would tell me the actual pressure. Or at least which tire.
They are real sensitive, to the point I pretty much ignore it.
Convertible tops are much better nowadays then they were. I had a 1996 Sebring convertible and had no problem staying warm.