Research the seller before bidding on that Corvette for sale
Just like buying any big ticket item from a private party, you want to know the person selling that Corvette on eBay. The first place to look is their feedback. This is something you should check on every item you bid on, not just cars. The seller's feedback page is where you can see how experience they are and how well they've handled other transactions in the past.
On the auction page look in the upper right corner under the "Meet the seller" section. You'll find their seller name, then just to the right in parenthesis you'll see how many successful auctions they've been involved in, both as a buyer and seller. There's also a feedback percentage. Obviously 100% is ideal, but even the best seller can get one or two negatives from customers who are simply impossible to deal with. That's why you need to also dig deeper and read the actual feedback that other eBay members have left.
In that same area click on "See detailed feedback" to go to a listing of all comments from either the buyer or seller of the auctions they've been involved in. You're primarily interested in their feedback as a seller, but don't gloss over problems they may have as a buyer either. Even if they have a spotless selling record, negative feedback as a buyer may indicate someone who's hard to work with, which is the last thing you want when purchasing something as important as a used Corvette for sale.
Look for Negative Feedback
If the seller has less than 100% positive feedback you need to find out why. Scan their comments/feedback for red (negative) or gray (neutral) icons on the left. Unfortunately there's not a quick link to find these. They're just listed with all the others. It can take a while to scan through hundreds (or thousands!) of listings. Tip: On the bottom right corner click on the "200" to display the maximum number of comments at once. This helps speed the process.
Once you find the negative or neutral comments you'll have to make a decision as to whether the complaint was legitimate or not. eBay's feedback system isn't perfect and the stray negative comment can be left by an impossible customer even to the best sellers. Use common sense and your own judgment. If the person complaining is ranting and raving, but the seller is calm and helpful in their response then take that negative with a grain of salt. Comment space is short, so you'll have to read between the lines of a situation. Just use your gut to decide if the comment is worth factoring into your decision to bid on that person's Corvette.