I pretty much live out in the country, and the roads are bumpy, but they're not that big of a deal.
Instead of going into the turn fast, and slowing down in the mddle, slow down before the turn and then accelerate out. If you go in fast, and then let off the gas towards the middle, this can cause you to slide. If you slow down before the turn, and accelerate through it, it should keep the car firmly planted giving you a higher exit speed. Just don't over do it.