Henry Winkler Fan Rolls in Coffin for Fonz to Sign at Michigan Car Show

Henry Winkler fans were dying to meet him at an autograph signing at a car show -- but one superfan literally took it to grave levels of adoration ... showing up with a coffin.

Yep, this fan queued up with a casket at the Marysville Hot Wheels Weekend event in Michigan on Saturday -- and 79-year-old Winkler went along for the ride, laughing as he signed it with a cheeky "Rest in Peace."

Thank God Winkler’s a good sport -- because that coffin really risked killing the vibe!

It’s unclear if the fan was hinting at Winkler’s twilight years, his own, or just proving he’s a ride-or-die Henry fan -- till the very end.

Still, this wasn’t a moment for doom and gloom -- it was pure celebration, with crowds flocking just to see the "Happy Days" legend in person.