BTW-I reviwed completed postings for last week on a 1999 Porsche 911 Carrera 4. I will be listing this car on EBAY this week. My listing is for advertising purposes only, I do not expect to actually sell via a bid process.
There were 15 cars listed. ONE sold at somewhere around KBB Wholesale value. The other 14 did not sell, mostly receiving no bids or having a top bid that was thousands under KBB trade value.
As I said at least for Porsche, EBAY has a very low success percentage and yields nowhere near PPT value for the sales it does produce.