Tbf, that list of stuff that you have done is mainly service stuff that you would have to do on any car really ,best stick with what you know as the next car may turn out to be even more trouble even if its a lot younger,mk3 is cheap to buy ,easy to fix,one day you will get to the end of that jobs to do list then what will you do ,im nowhere near the end and it does my head in somedays but I accept it as an old car that's allways going have a fault or two so i just carry on as I know a newer car will cost me a lot more in the long run .