Very true Pete!
Today I witnessed a good example of this. Today the Prince of Monaco auctioned 38 of his 100+ vehicle collection, including a GMC and three Dodges.
I witnessed this auction as I am holidaying in the vicinity and wanted to have a look at a car auction; also never seen military vehicles being auctioned.
What looks like a "plain Jane" 353 to me, with nice bodywork but unknown mechanicals - see the auction catalog entry and judge for yourself - was estimated to do 10.000 to 20.000 EUR, and it made 13.500 EUR.
Star of the auction was the Dodge Command car with brisk bidding ending at 45.000 EUR; the fifth best price out of 38 cars auctioned.
Clearly people are willing to pay a premium for a vehicle with no provenance other than being owned by someone "famous". It also helps auctioning vehicles in a town which hosts extremely wheathly people. In this case I guess it doubled fair market prices at least. There were a few regular HMV collectors present, but they were not impressed by "rare", "6 driven wheels!", or other (non)qualifications given by the auctioneer, and bid up untill roughly half the hammer price, which to me is another indication of what those "in the know" would be willing to pay.