In my opinion the cop class is perfect right now, the only needed thing is avoiding damage during tazer animation.
Helicopters where already nerfed, seasparrow it's easy to takedown and rustler it's really hard to drive. Also rustler can handle only 1 player so no point to nerf it.
Trust me, we only need to balance the civilian class costs and mike already working hard on it, the next update will significantly affects the server economy and we'll finally see the game balanced when he add the new features for civ like drugs system and other cool features already suggested.
Making the civ class profitable will reduce the players playing as cop. Just give time, he can't do shit, it's really hard to keep the economy balanced, same for drugs system, really hard to keep it balanced, imagine 300+ pings players abusing drugs... imagine a server full of money and no one intrested anymore in robbing/earning.
-1 cop nerf
+1 civ buff