I’ll repost what I did already. Had the intermittent start issue for about four years. After a supertech at a dealer kept my car nearly two months, he was able to find the problem after disecting the car part by part: 1) new clutch sensor 2) ignition relay switch Problem solved and absolutely no issues.
Had same issue with 1999 GTI for four years. After multiple failures at different mechanics I finally took it to a dealer. Took them a month and a half to find the issue: new clutch sensor and ignition relay switch. Problem solved.