try another coil mate, vw's seen to have a bad problem with coils, when it gets warm it seems to pack up, then when it gets cold again it will work. Only a couple of quid so werth a try. When it happends next be prepared, take ur tools an remove one of the leads too see if you have spark, if you dont its could be the coil, if you do still have spark then its a fueling issue. Has it had a new module ? Its an intermittend problem which is the worst to try an diagnose. It would cost u a fortune to take it to a garage to sort, cus they'll just try something, if it doesent work, try something else. At the end you'll get a huge bill. Better off investigating urself if you can to narrow down the fault.