Its hard to tell with your pics what you need and wont you don't with the whole laying out in a line approach. Personally I like to have everything on top of each other and just hide what you don't want to see and when working with multiple meshes using wireframe etc, far easier to see how things line up etc with the LODs etc. So ye, can't give any feedback on col0 as such because of that.
col2 is looking better but can see some useless verts/edges that can be optimized etc, mainly the two rear inner verts coming up from the track bits, they don't need to be there and the turret is still far too detailed, all that lip is going to do is make it harder for players to walk on the top of the turret rather than giving it more detail, just make the top flat or if its a big drop, a ramp at the most too the two levels.
col1 still needs a lot of work. Like I said originally, its best to make col1 from scratch rather than trying to optimize down a LOD as they can be and need to be so simplistic, its soo much less work. Literally all the turret needs to be is a box and the same pretty much for the hull. Given a proper side and front pic I could quickly draw it quickly but can't see any to hand.
Also for the turret, it ideally should be its own object on the wreck mesh with its own cols so that when the vehicle is destroyed, the turret is pointing in the same direction as it was before it blew up. Most of PR's vehicles aren't setup like this and just have their turret snapped forward but I'm pretty damn sure its possible and think you just set the wreck up with the same hierarchy as the main model, just simplified to only have the main components you want in their right place which is basically only the turret in this case I think.
CTRifle wrote:
TBH I don't bother with unique wreck materials myself unless there is a good reason an object needs it. Your better off just assigning the normal materials to the wreck and keeping things like glass, glass instead of a "wreck mat"
Also on your naming, would call it "armour_front" etc rather than "metal_front" and also the important thing to name in the materials is not the sub object name but the actual material name. Right now after exporting all its going to show in the .con/.tweak file is "Material #1" for metal_front, "Material #2" for wreck etc.