I passed first time there. My friend gave me the best tip which really was what did it for me-
On Showground Road, when you come out near the traffic lights, don't be impatient. The rule is you need TWO lanes free before you can come out, so don't get impatient and rush out. Just wait until there's a gap or the traffic lights turn red (to stop the oncoming traffic) before you come out.
I thought I failed on a roundabout because I waited, went in, and then suddenly a car popped out of nowhere. But instead of continuing to enter the roundabout, I stopped just crossing the entry point but not enoughso to stop the other car going through. It's a penalty, but not a fail. So it's all good.