I have now had the car 6 weeks and as part of 'getting-to-know' the car I checked the hydraulic fluid level about 4 weeks ago and I remember tightening it. Since then it has not been touched by anyone. Two days ago I found the cap loose so I tightened it thinking I may not have tightened it properly after checking the fluid level. Only 1 day and 110 miles after tightening I discovered that the hydraulic fluid filler cap was loose again? I checked that the thread is OK (not cross-threaded or damaged) and tightened it very tight this time. I am assuming the correct cap is fitted since it screws on OK and I am now monitoring this in case it comes loose again. Has anyone else had issues with the cap coming loose on its own? Is it a recognised fault?