This Porsche 924 Carrera GTR was constructed in late 1982 as the lone all-tube-frame example built by Holbert Racing in Warrington, Pennsylvania.

The car was sold upon completion in 1983 to team owner and driver Paul Miller due to a shift in focus by Holbert Racing before the ensuing SCCA Trans-Am season.

It was piloted by Miller to nine top-five finishes during three seasons of Trans-Am competition, also undergoing frame, body, and engine modifications in accordance with evolution of series rules.

After time with three additional owners it was purchased in 2012 by the seller, who commissioned a restoration to its 1985 form before displaying it at Rennsport Reunion in 2015 and racing it at the 2018 running of the same event.

A turbocharged and intercooled 2.25-liter Audi inline-four powers the wheels through a rear-mounted Hewland five-speed manual transaxle equipped with a limited-slip differential.

Additional features include Kugelfischer mechanical fuel injection, dry-sump lubr...