This problem affects all cars.
The cars glitch, somersault in the air, go under the map and suddenly veer off the road and crash into trees, walls, buildings etc. They also rubber band both forwards and backwards.
It happens in the countryside and in towns.
Today they have been undrivable.
Every car driven today has done this.
We have logged off and back on.
Left it for over an hour logged on again and it's still happening.
Restarted the server, it's still happening.
Sadly this has been a problem forever. The more players on the server (especially those with high ping) make it worse. With Shroud and Summit playing even vanilla servers have been a problem. I drove cars just fine when the server was 2-40. Today I lost a character I'd kept alive for 2.5 weeks - raided a major base, killed dozens of "bad guys" and the poor dude was done in by a glitched Olga. RIP.
I have no earthly idea how this engine and net code will be used for ARMA 4 where 120 players is normal as are dozens upon dozens of vehicles, planes, helis, etc.. Hope that if they fix it for AMRA 4 we get a patch update to fix it for DayZ (though I'm just as much if not more an ARMA player - been playing since Operation Flashpoint in 2002.