The hardest part of driving with the steering wheel on the wrong side (RH steering in the right lane or LH steering in the left lane - I've done both) is passing.  You have to have a passenger you trust since you have to move completely to the other lane before you can see if someone is coming and by then it might be too late.  Not an issue on motorways, dual carriageways or autobahn but downright dangerous on 2 lane roads without a passenger.  I owned an American car while living in Britian and a UK car while living in Europe.  But they were both sports cars and driven very little by myself.  Those were the days!