v0.1

I'm just starting with the police cruiser but intend to change all of them.

The police cruiser now goes much faster, but takes a little time to get up to top speed. I've also reduced the 'breaking' when you release the accelerator, but it causes coasting at minimum speed to go on for quite a while, so use the brakes. The front bumper is significantly tougher, and the engine is slightly tougher as well.

v0.2 - I got a ticket to anywhere

Included some of the easier vehicles that don't require suspension overhaul to deal with higher speed.

Rally hatchback - Much higher top speed, slightly reduced acceleration especially at the top end, more roll.
Black modern pickup - Slightly increased top speed, reduced top end acceleration, more roll.
Old pickup - Slightly increased top speed, reduced top end acceleration, more roll, tougher engine and front bumper.
White Sedan (not Taxi as previously stated) - Somewhat higher top speed, reduced top end acceleration, more roll.

Note: The rally hatchback was already prone to tipping when you hit bumps and curbs, it will do so even more at the new higher speed. I have future plans to attempt to reduce the paper airplane feel of airborne vehicles, but want to get the speeds done first.

v0.3 - Maybe we can make a deal

All hatchbacks - slightly reduced tendancy to jump on insignificant bumps in the road
Hatchback and Pizza - slightly incresed top speed, slightly reduced acceleration especially at the top end, more roll.
Taxi (for real this time) - Somewhat higher top speed, reduced top end acceleration, more roll.
All Wagons - slightly incresed top speed, slightly reduced acceleration especially at the top end, more roll.
Red modern pickup - now matches black modern pickup
Blue sedan - now matches white sedan
Green muscle car - [WIP, don't use muscle_car_variant_shiny if you don't like it] Much faster, still working on the handling because it's pretty wild, but fun.
High end exotic - Much faster, reduced tendacy to flip when turning and using handbrake.

v0.4 - Maybe together we can get somewhere

Found physics damper. Removed physics damper on all vehicles. They act as if they have more momentum now, both rolling and laterally.

v0.5 - Any place is better

Reduced vertical air damper to almost nothing so vehicles float less. Increased airborn gravity to normal, should also slightly reduce floating. Reduced negative decceleration on several faster cars as it was overkill after getting rid of the physics damper

Rally Hatchback - slightly reduced acceleration curve

v0.6 - Starting from zero got nothing to lose

Increased angular damper while airborne. Not really more realistic, but it helps keep the vehicles from flipping when hitting rocks and landing after jumps (really irritating). You can feel the correction but I don't think it's too bad, I may increase/reduce it later as I play it more, let me know what you think.
Increased massbox weight of all vehicles to somewhat realistic values. Hard to tell how much impact this has, but I wanted to do it.

Green muscle car - more tweaks, front will slide more when cornering and generally pivot and spin less on the front end.
Black muscle car - is now a slightly steadier, slightly faster version of the green one.

v0.7 - Maybe we'll make something

Reduced friction offset for any vehicles I haven't already. This effectively lowers the centre of mass to a more reasonable point. Some vehicles may be a little too laterally stable when turning for now as a result. Will correct later if necessary.
Reduced lateral slide correction on all vehicles (they slide more now when turning at high speed or power sliding). I may add some back in for some vehicles if they slide too much. I kinda like it though because you are actually going pretty fast most of the time and you would slide taking right turns on small town streets at 40 mph all the time. I still find it controllable, maybe even more controllable once you get used to it because it's predictable now that you slide instead of flip most of the time. This mostly effects the Rally hatchback and Modern truck which had very high resistance to sliding.

Police cruiser - decreased suspension travel a bit to avoid wheels clipping through body and bottoming out at silly times, makes it a little more stable too. Also increased suspension damping a little, it's still slightly under damped, but it's a po-po not a race car. Tried to rework the handbrake to stop it from spinning like a top, but lost my test vehicle, so it's my best guess until I find another one.
Rally hatchback - decreased acceleration.
Regular hatchbacks - tweaked handbrake a little.
High end exotic - slightly decreased acceleration. Reduced suspension travel so it's a little stiffer and the wheels don't clip through the body as badly. Reworked handbrake friction so it doesn't spin like a top anymore.
Wagons - Increased base wheel friction as they were previously held on the road by sheer corrective measures.
Muscle cars - Increased friction while suspension is compressed, for some reason it was lower than the other vehicles.

Extract to State of Decay directory