Still doesn't help with people mis-labelling things. Until the mass can be trusted to use the forums available to them properly, you're only making life more awkward by giving them choice.
In theory I have no issue with the idea, and in a perfect world it would help massively. The trouble is, people are stupid.
We're not leaving in a perfect world, people make mistakes, but that's why we have moderators here, a full army of them. And if they're not enough, surely we can get some more: Will370z, Darren-B and many more.
But, clearly, we do need two separate subforums in the FS section. If it was up to me, I'd do it even more distinct like:
FOR SALE:
1. 370z PARTS
- exhaust and intake
- engine & gearbox - plenums, spark plugs, clutches etc
- audio & video - ICE, subwoofers, satnav, speakers, headunits etc
- body - bumpers, skirts,
- suspension - coilovers, camber arms, traction arms etc
- wheels and tyres
- power kits - turbo, supercharging, custom gauges, pods, fuel systems
- interior - seats, trims, dashboard
- cooling - radiators, intercoolers, meth injections etc
- brakes - discs, pads, BBK, lines etc
- miscellaneous - SMD's Jaaaag gloves, stickers etc
2. 350z PARTS
same as above
3. CARS
- 350z
- 370z
4. NON ZED RELATED ITEMS
For instance, new 370z owner, comes on the forum and wants to buy a 370z exhaust. A lot easier to search in the specific subforum, rather than browsing to hundreds of random for sale threads for both 350z and 370z