Dale Earnhardt Jr. — Lures New Crew Chief Amy Reimann … with Giant Diamond Ring!!

Dale Earnhardt Jr. is taking the ultimate checkered flag … he’s getting married! 

NASCAR’s most popular driver proposed to longtime girlfriend Amy Reimann while vacationing Wednesday in Germany. Reimann posted a pic — naturally flashing her engagement rock — in a Lutheran church Dale says his family attended 300 years ago. 

Reimann and Earnhardt have been dating since 2009 … and you gotta figure she knew the question was coming sooner than later. Dale gave her a shout out in a commercial he shot last year.

You don’t mention a run-of-the-mill GF in an ad you know will air constantly during NASCAR races.