Two things that are really missing in OFP are add ons to vehicles. Hummers for instance I dont think I ever saw one with a gun on top but thats probably no problem to add with the turret. However there are two things that maybe more difficult.
One is a flare dispenser on the Hummer. It's a thing at the corner of the hummer has four tubes with little cilindirical packages built in. It holds flares for night time operation etc. They shoot out at a angle aboue 30 degrees I believe. I can snap some shots and get them scanned when I get home. THis may be possible and added to the list of weapons.
Tanks have a few things Id like to see. Not only do they have the above flares they also have smoke screen abilities. Also what about reactive aromor is that possible at all?