If there are cars parked solidly both sides then it's give an take surely? Otherwise, the one with the obstruction on his side of the road gives way to the on coming vehicle that has no obstruction. At the end of the day it comes down to common sense and tolerance for your fellow road user. Unless of course you are one of the following:
A white van man with an attitude.
A woman in a Range Rover
Anybody who is on the mobile
An oap in a cap with tunnel vision and cataracts
A mini cab driver in a Toyota with no hubcaps
I could go on all night!
There are as many answers to that question as there are cars. Are we talking about cars parked opposite each other, or is the car on your side of the road closer than the one on the other side; or vice-versa.
It might be worth remembering that only pedestrians have RIGHT of way.