Take the 510 for a long drive even offer to buy him some gas, to see how it runs or over heats, or dies even when driving,, , if owner doesn`t want to then i would pass .. IMO,,The miata is a 100% safer car if in a wreck ,,even if it is a convertable..
Ad mentions coil overs but doesn`t say they are zx struts with the bigger zx brakes.