There were people who liked the Mad Max-y car-building side of the game. ... Those playstyles and more besides were both possible and viable. All of them have been to some degree curtailed so that they no longer work or are much more tedious and/or unreliable.
So as one of the developers who has been making a lot of player visible changes in the vehicle code, can I ask you to specify what about Mad Max car-building that has become so much more unreliable?
Since I started playing about 4 years ago in early 0.C, the vehicle system has changed in a couple of significant ways:
1. electric motors have been adjusted a couple of times, but the net result is there a wider range of electric motors, from very small to fairly large, and all of them get decent efficiency
2. gasoline and diesel engine sizes have standardized and made to support multiple fuels
3. steam engines and freaking huge gas turbines have been added
4. infinite fuel engines like the vortex engine from blazemod have been simplified and standardized
5. lifting and jacking requirements have been added, but satisfying them is fairly trivial
6. vehicle parts have descriptions of what they do when you install them, making it easier to figure out how to configure your vehicle
7. electrical power generation got reduced, but so did the energy costs of most things - you're no longer burning 250 battery charges/turn just to keep the stereo going.
8. rams have been added to vanilla, and most vehicle parts have gotten decent amounts of armor
9. the way that vehicle speed is calculated has changed substantially, but it's still easy to put together a deathmobile that will travel 15+ tiles/turn and most people don't like driving that fast. Vehicles don't have nominal top speeds of 3000 mph any more, but if you put a 6,000 HP gas turbine on your racing bike you will go crazy fast enough.
10. boats were mainlined, and vehicles can now be made amphibious and you have a variety of choices in your boat hulls
12. bike racks were added, so you can attach a little scout bike to your deathmobile, drive from town to town in your deathmobile, and have a little scout bike to scout inside a town. you can even put bike racks on your scout bike and attach small vehicles to it. (and your scout bike can be amphibious, if that's your thing)
12. there's a limited autopilot to cut down on the tedium of driving from point to point
13. we've got working prototypes of towline towing and helicopters
14. there's a definite plan for adding vehicles that span multiple z-levels themselves, and allowing ground vehicles to drive up and down ramps
15. various other convenience features (single button powered curtains for your entire vehicle, vehicle heaters, off-road tires, the mechanics profession that starts with a welder and welding goggles) have been added
From my perspective, going Mad Max in CDDA is easier and better than ever, and if for some reason you don't like some of the changes, modding even higher performance vehicles is really easy.
The only things that I really acknowledge as nerfs are:
1. foot pedals no longer produce the equivalent of 15 horse power, so some power generation strategies got busted
2. you can't fix everything with duct tape
Tastes very, but I'll trade those two drawbacks for all that other stuff.