Personally I wouldn't advertise another car with Ebay Motors UK. The process of placing an ad was long and complicated (especially for the first-timer) and many 'buyers' were unwilling to bid as I was a first time seller. This kind of snobbery isn't very helpful.
Their customer support is slow and it is impossible to talk to someone on the helpdesk. Their 'contact form' is not at all intuitive as you need to select your comments from a series of menus.
Overall, it's not the selling (or buying) experience it's cracked up to be.
I ended up selling my car on Auto Trader's website, which incidently is very good!