volkswagen bettle

Good day. My inlaws bought a 1999 Beetle and it runs good ,but sometimes when you drive it and shut it off ( e.g. at the grocery store.) It won,t start. Turns over fine but will not fire. Then if you let it sit for a few minutes , like an hour , it will start right up. Any idea,s would help before I take it to the dealer. Thanks in advance, Regards Martin

Does the chck engine light come on?