Mine does the same thing, went to VW to get a #30 relay. First the guy couldn't find the part # for it, so i had to take the one out of the car to show him. Then he tells me theres none in stock. The one i have i the car is a black one made in germany. When i put the relay back in, the car fired up straight away

(Think because it had time to cool down) and drove excellent for a while, then went back to normal?

, think the relay may be getting too hot.