No problems with any cars at all even though I cycle down a pretty fast country road, probably helps that with panniers my bike is pretty big and wide. I find the road much more scary in the car, it doesn't seem wide enough for 2 cars to get past each other in some spots.

Closest call I had was with a horse poking his head over a fence which I nearly crashed into, also a few aggressive bunnies playing chicken with me.

Best thing I did was buy a big yellow jacket, there's no excuse for not seeing me.