Completed the main story this morning The only mission I haven't done is the casino robbery I know you have to get the code off CJ's girlfriend but everytime I go round there shes never in.

The RC plane missions are hard, there are 3 in total and the 3rd is a piece of piss compared to the first two. Here are some tips that might help

RC mission 1: The objective is only to protect the ariels not shoot every single plane down. So aim for the planes that are most likely to hit the ariels. Most of the planes drop bombs and miss, If they do then don't waste time shooting those ones down just look for the ones that are still carrying bombs. Also use the map in the bottom left of the screen to help pin-point where the planes are coming from.

RC mission 2: When you fly off the roof go for the nearest delivery driver in the van as soon as you shoot him he will get out the van so it's pretty easy to get that one done quickly. Next get the bloke on the push bike which is nearby. again pretty easy to kill him. The 3rd nearest target is another van. When that one is done you will find the two remaining targets are a lot further away. You will need more than 1/2 tank of fuel to kill these and return. The two men on the motorbike are the hardest. Try and sneak up on them and kill them in one swoop because if you don't they will speed off and it will be hard to catch up and kill them.

RC mission 3 - should be easy to do in 1 or 2 attempts

Hope this helps