I know what you mean, Ive had numberous company cars over the years and things tend to be ok until around 65000 miles then one by one things start to go wrong, thats why the companies get shut of them at 3 years and 60000 miles, they know its a risk and might cost them money if they keep them longer.
Best to get a new one before its first MOT is due ideally on that basis.
Maybe, but to buy a new JCW is Ł25k, which is a lot of money for a mini and judging by my bosses Cooper S, which has been his most unreliable car for the last 10 years, doesnt always bode well in buying new. It not our main car, but the wifes, so we are guessing we will get over these issues and be OK for a while longer. The car came with lots of repair bills, but not the usual things like the sump and psm. We have a 300 hp Focus st for long distance work, this is a pottering car and when that goes wrong, then the daughters Ł500 polo is reliably in action while she's at uni.