Buick’s turbocharged 3.8 liter V6 should have ended when the Regal went front wheel drive in 1988, but this final episode of OldCarMemories.com’s series tracks its unexpected last stop: a 1989 Pontiac Trans Am. The engine used Pontiac heads instead of Buick’s own and reportedly paced the Indy 500 as a genuinely stock car, a first. Watch to see how a mid size sedan engine ended up the fastest thing on a GM showroom floor.