Just so you know guys, there's user created missions out there now that have modded content in them. All of them by the same guy, and all in 1hr deathmatch (as far as I'm aware):
http://rsg.ms/1l9OEnL - Airport deathmatch. Has Cargoplanes (the one from Trevor's mission where you fly into the back), pink Laser jets, the Romero Hearse and a few other cars.
http://rsg.ms/1l9Oxs4 - Airport deathmatch. Has 747, chrome cargobob and pink Laser jet spawns.
http://rsg.ms/Kqvn2X - Dirt track deathmatch. Spawns blimps and black Cargobobs with Trevor Phillip's Enterprise graffiti on it.
http://rsg.ms/1cguu33 - Golf course deathmatch. UFO easter egg spawns above the course. Also has space docker spawns and a red Skylift.
So be sure to add these and try them out before they're patched (if)/ removed. I might come online tonight to play around with these, so I don't know if any of you are down to play around with this stuff? Blimp Wars anyone?