Anyone up for some Rooftop Rumble grinding? Around 2 minutes and minimal work for $18,700 and around 4,300RP.
Just a few tips for R.R. grinders, have one person in the front and another stationed in the back with an RPG/grenade launcher or explosive of any kind to blow up the vehicles along the side with the Gauntlet and SUVs. This will take out almost everyone. Shoot down the last few members, and should the guy with the document manage to attempt a getaway in the Fugitive, have your vehicle parked to where he'll try to go around it and end up driving into a wall. Kill him, and quickly hop in your car. Have the document driver in front and the other player(s) behind him/her, fighting off the enemy Grangers while the document holder makes a run for it. Then on the 2nd fork in the road going up Vinewood Hills, make a left instead of going right. This will shrink down the amount of time taken during the mission. Going right is about a 1/2 mile, while going left is about a 1/4 mile. Then slide into Martin's driveway, and you're done. Rinse and repeat until satisfied.
I can't be bothered with Coveted, since I'm crap at sniping, so if you're in the same boat as me, then try the above techniques in Rooftop Rumble to get around the same payout.
BONUS: Have your buddies in the same crew and make sure you're playing with friends. This will add to the total RP you earn during the mission, effectively boosting it to around 4,500 - 4,600RP.