Just my opinion but:
1) You have sections, so what sections would be useful, eg wiring, parts books etc? Brochures, road tests & mag articles, wiring diagrams, parts books, technical data. I'm sure there could be more.
2) Do we allow guests to access the downloads section, either to view and/or download? No - we want the forum to thrive and putting resource behind a paywall (ableit a free one) is a good incetnive to join and take part.
3) currently it is set to moderate each file after it has been uploaded before it is available to download or should any upload be auto approved by the user? Sadly I think they have to be moderated - some groups have had some really innapropriate stuff uploaded.
4) current setup is max file size of 500Mb which is pretty large, is this too large (we have the space)? Sounds generous but if we have the space and we're moderating it should be fine.