About the only thing that's improved in the last 30 years is fuel efficiency.
Expensive to replace electronic keys: I can't even get a door key cut for my Pontiac Wave; nobody stocks the blank. It's supposed to prevent theft. I have never had a car stolen, but I have lost keys. - No thanks.
Roof racks that require you to purchase another roof rack to attache to it for $600. before you can use it. Check out the '92 technology:
You could get a key cut for $2 bucks at a hardware store. The hood stayed up by itself. The roof rack crossbars could be adjusted fore and aft. The older '83 was even better; the rear crossbar kept the back window dust-free so you didn't need a rear wiper.
I applaud the return of actual HP in cars a few years back, but I'm not so happy with the way you can only get the high output engines with the most expensive trim. Back in the day, a few hundred more would get you the the top dog engine by clicking a box on the option cheat, now you have to pay an extra 30K. I guess they want to keep sales down so they meet the CAFE rules. Do they still have to meet these average fuel economy rules?
Dough nuts instead of spares (another concession to fuel economy) - no thanks; I just have to buy an additional tire. Who wants to drive at 50 mph for the next 100 miles or more before you can get a new tire.
Fancy electronic dashboards - built in obsolescence.
Cameras - no thanks extra unneeded expense.
17 airbags - I would rather spend that money on better (better-gripping tires.)
High centre of gravity minivans and SUVs replacing low centre of gravity 50/50 front rear weighted wagons - No Thanks.
BTW my '09 Pontiac Wave has more new parts at 60,000 miles than my wife's '93 Toyota Corolla (not counting wear and tear parts like filters/pads/rotors/light bulbs). I"ve also noticed that they have geniuses designing ever more clever ways of making it more difficult for the home mechanic to do simple things like change a light bulb or a spark plug - a trend that started in the '70s and continues to this day.
Despite your comments, there are lots of improvements over the last 30 years besides fuel economy. Here are a few:
Anti lock brakes
6/7/8 speed auto transmissions
all wheel drive
huge horsepower out of smaller, lighter engines
way better tires
electronic stability control
efficient use of space making most cars more useful
clean, quiet diesel engines in private vehicles
100k spark plugs
3point seat belts at all seating positions
better crash protection
better build quality
better rust prevention
Cars today routinely go well beyond 100,000 miles with regular maintenance.
I also wish there were more wagon choices, but wagons do not sell here in the US.
Thirty years ago a 1984 Camaro z28 optional L69 305ci (5.0L) v8 was a $530 option (almost 5% of the Z28 base price). It was rated 190hp/240torque, the most powerful available Camaro engine and it was only available on the most expensive Camaro - the Z28. The current base Camaro comes with a 217ci(3.6L)V6 rated 323hp/278torque.
Sometimes our memory makes things better then they actually were.