Now for the disadvantages, and there are many. First and foremost, you're bidding, literally, on a pig in a poke. In most cases, you can't physically inspect the car, and you're relying on the honor system. Whenever you're buying a used car, the honor system is strained to some degree, and often to the point of outright misrepresentation and lying. After all, the seller wants to move the vehicle, so he's bound to put some extra spin on it to make it sound better than it actually is.
Throw into the mix the fact that dealers are very often the ones offering Corvettes for sale on these online auctions, and that compounds the problem by several orders of magnitude.
There are, indeed, some very reputable dealers who offer vehicles via online auctions. Unfortunately, they are rare birds since this type of auction readily lends itself to the unscrupulous and even to outright swindlers and crooks.
That been said, if you're hell-bent on getting involved in online auctions for a Corvette, here are some things to remember. First, don't place a bid on the car before you know more about it. Contact the seller with a list of questions regarding the car's actual mileage, the number of previous owners, matching numbers, realistic description of its condition (not the blurb on the internet auction description), known problems, and the availability of receipts for any work that has been done to the car. You also want to know about anything that is "incorrect" about it, especially if this is going to be an investment as well as a fun cruiser for you. Be sure to ask the seller to fax you a copy of the title and a tracing or digital photo of the VIN number. The reason for this is to establish there is no lien on the vehicle (the title will show if it is encumbered or clear).
Ask the seller to e-mail you additional digital photos of the car showing multiple views (15-20 shots at the minimum) of all four sides, engine compartment, interior including the seats, door panels, dash, instruments, and the odometer showing the mileage (compare this number to the mileage shown on the title; the odometer figure should be somewhat higher). You also want to know about any collisions the car was involved in-replaced fenders, body filler on the rear quarters, and so on.
You might also ask the seller to shoot a videotape that shows all the above views as well as his commentary if you're really interested in the car, assuring the seller you'll return the tape if you don't win the auction or decide against bidding on it. These are not unreasonable requests if you're a serious candidate for buying the car and the seller is serious about doing a deal, especially when you're talking about a serious amount of money.
Ok, so let's say the seller is very accommodating and has provided you with everything you requested. You like the car very much, and you're ready to place a bid. As soon as you do, you're outbid by another. You counter, and you're outbid again. You figure someone else is really hot for this car, but you may be dead wrong. You may be bidding against a shill bidder, a common practice used by sellers to drive the final price of the vehicle up. And, yes, this is against eBay rules and just about every other auction's rules. Although all the major online auctions try to take active measures to prevent shill bidding, in reality, there's not too much they can really do about it.
Oh, yes, did the seller mention that this big-block Tri-power coupe was only driven by a little grandmother to church on Sundays in the description? Don't be a babe in the woods here!
The real downside is there's very little recourse for the buyer and the seller if the online auction goes awry for some reason, or either party fails to live up to their end of the bargain. The auction host will give a warning, which is really just a slap on the wrist, but that's about it.