Pick the buyer when you mark it sold. That is what lets them review you.
An item bought through checkout is marked sold for you. For anything agreed off checkout, such as a vehicle, a free item or a collection, mark it sold from My listings and pick the buyer from the people you talked to.
Only the buyer in a recorded sale can leave a review, which is why picking them matters: it is the difference between a review and no review. The database refuses a review from anyone else, so nobody can pay for a good one.
Reviews and completed sales are what raise your Trade Rank and, eventually, earn Trusted Trader.
