They used to. It was implemented about 3 or 4 years ago but was dropped after a few months due to the fact it was as detrimental to the members as the non members. I.e. a member may have been in the market for a certain used part but the non member selling it not being able to start a thread meaning both were impacted.
They did 2 things to solve it
1 - they allowed wanted and general sales to be posted by all users, I believe cars for sale is the only members only section.
2 - They allowed users to become full members for £5 for 10 years.
I've been a full member in the past but I'm unable to use any of the perks. I'd like to think that I've paid my dues in other ways with advise, assistance and a loan of parts over the years.
Maybe I should charge £1 a time from now on?