There's a pretty specific list. I'd open up the default bus and default subway in Zmodeler or 3ds Max first. Then, look at the model hierarchy. It should have all the dummies and parts listed and organized (for example, wing_rf_hi_ok and wing_rf_hi_dam should be a subsection of the wing_rf_dummy in the hierarchy). If you can't pull it up I can post a full list.
Then just make and position your dummies and parts, set up the model hierarchy, and export.
E: by the way, a dummy tells the game engine where a specific part is. It's mostly used for damaging the car and for animations. If the dummy was in the wrong place on the driver side door, for example, the door might swing way up in the air when opened. Dummies are needed so the game doesn't crash, and you need to build your hierarchy around them so the game knows to replace your brand new front bumper with the broken version when you hit a tree.
E2: This image is from one of my tutorials on converting cars. The third screenshot down shows a cleaned up hierarchy. It might be a bit different for SA, but hopefully this gives you a rough idea of what you need.http://i.imgur.com/aBATK.jpg This post has been edited by fireguy109 on Friday, Jul 27 2012, 19:20