Much to my surprise it seems giving way on Roundabouts its completely optional..and it would appear even when you have decided you don't feel like Giving way and slam into another car at 30mph its perfectly acceptable.
In fact failing to give way...causing an accident (Not called Accidents now days...Now called Collisions) and then driving off Is just fine,as long as you return to the scene of the accident (no one seems to know what a reasonable time limit is) and give your details,you can then leave again before Police arrive and you have nothing to worry about.

Slight sarcasum...My wife was driving my Galaxy (Shame wasn't the Saab93) on way to work,enterd a roundabout (small one and you can see all entry/exits) with the intention of leaving on the third exit.
Sadly the bloke entering the roundabout didn't feel like giving way and slammed into wife as she was just passing the second exit...result was she bounced off the Roundabout and ended up past the third exit.
Other car drove off...wife hit the Horn and flashed her lights (Happened at 2045hrs) and matey came back after about 5 mins,by which time people had come to have a good old nosey.
The first thing he said to her was "Didn't you see me." my wife in a state of shock said yes she had,its then he said "Well why didn't you stop...! " followed by "I hope you have insurance".
Wifes phoned me and ive flew down to the collision and took his details and asked what happened,to say I was gobsmacked by his attitude is a major understatement.
He fully blames the wife...and states she should have given way to him...wouldn't except he has to give way to the right (Obviously assuming the other party is already on the roundabout).
Now this is the bit I find hard to accept...Police officer arrived just after the other drive left,asked if anyone was injured to which I said no and sent the wife home with neighbour who had taken myself and kids down,ive asked him will the other driver be getting a vist regards failing to give way and driving off.
Answer was a deffinate No...as he had returned (all be it some time after) and gave details and no one was injured it wasn't a Police matter,so failing to give way and driving off isnt a big deal then.?
Ive been down to report thye other driver yesterday as wife has (Genuine) whip lash type injures,Police said that now makes it serious enough for them to make an accident record,but they cant prosecute the other driver (or look into doing so) unless the insurance company instructs them to do so...

Insurance company basicly laughed and said WTF...so its an odd situation,wifes been rammed by some silly middle class duffer who states drivers give way to the left...Police say they cant act unless insurance company tells them to go after him and unless he admits liability the claim will be settled by my bloody insurance and Im liable for the excess.
The really scary thing is...what if that had been a Biker or god forbid a pushbike,id say the latter would have been a fatality,and this guy is driving around without a care in the world.
Bloody boiling...yes just a bit.
