A few things I see why this is bidding up like that and in comparison why you had little action:
1) The bidders don't know what they're getting into and the auction is getting people into a bidding competition.
2) Your ebay ad had a fixed price, not a low auction price, that was not all that far from a clean titled Roadster's price. You priced your self out of a market and landed in a price that make the seller push over to the edge of buying one that has a clean history.
3) Your ebay ad had zero pictures, which to me, looks more like a fly-by-night Nigerian ebay/car scam and I'm sure others felt the same.
If your serious about selling *any* car or anything on ebay, list what your trying to sell at a low opportunistic price with no reserve. I don't take auctions with reserves seriously honestly. And everything I list on ebay has a low starting price with no reserve. The market will tell the true worth of your product, and most of the time due to the bidder war mentality it goes higher.
I also find that when selling a car or item to be very forward with the history of the vehicle / item. First I don't want others to fall into the same hole that I did. And if I have to take a loss then I will. But in the end it all works out. I'm sure this will catch up with the ebay seller
sixtrentacar707 who's offering this Roadster and not being honest with the buyers if the transaction goes through.
This world and the Internet is a very small place, in particular the Roadster community who look out for one another's best interest.