Barrett Jackson.
Or try Gooding & Company. I'd invest in the ever classic black Fuch alloys w/ the machined lip. They compliment these cars well. Ebay those BBS wheels. They'll go quickly. VW guys love to run them on their modded MK II's and so forth. Just throwing some ideas out there.
The reason I would recommend the collector car auction route would be due to them continuing to attract affluent (even eccentric) buyers who are in the market.
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