Just had a few days holiday in Northumberland. Just before setting off there was a warning of low coolant level which I've never seen before. No sign of a leak that I could see.Put in a couple of litres of water. Drove 200 plus miles, and a little local driving, got the warning again. Filled it up again, and a few days later drove back home. Must be going somewhere but can't see where. Hope it's not the head gasket. Whilst up there, got another warning. Can't remember the exact wording but something like "Drivetrain problem, full performance not available, drive moderately, and get it checked out". This appeared and disappeared 3 or 4 times over about 10 mins, and then disappeared for good, not seen it since. It pulled the glider trailer there and back with no problems, everything seems quite normal. Any ideas?