Lots of great advice in this thread, but you really need to try the different mods to see what works best for you. Also, dont be afraid to switch up your mods to compliment your weapon / vehicle loadouts, the mission you are currently in, or to counter your opps loadouts.
God Tier: Pioneer
Good tier: Espacio, 4x4
Dont use tier: everything else
I dont say this to be mean.
But rather I say this to illustrate how possibly broken vehicle balance is.
It seems Im in the minorty here but from my perspective, at least in silver districts, skill cap has gone up, not down.
Then again, I was having packet losses as high as 12 the last couple days, so who knows.