I owned a 95, 97, 98 and 2000 Neon. The 95 had the head gasket and then the head replaced under warranty. If I recall correctly they changed the head design once and the gasket design at least twice. The car then ran for 200,000 without incident.

The 97 never acted up on me but I traded it in on the 2000 because of piston slap when cold. The dealer wouldn't do anything about it. 4 years later I bought a cheap 97 Neon with bad head gasket and 70,000 on the clock. Turned out to be the same darn car I had traded in. The gasket was replaced along with the head bolts and that was that. I just ran with the piston slap.

It seems the cam seals in the head were prone to leaking some oil and the way it leaked I'd have bet money it was the rear main.