RP Farming: Earn 100 RP Every 8 Seconds

Here's a brand new method to earn 100 RP every 8 seconds in GTA Online...

1. First off you will need to be level 70 to get this mission from Lester, or you need to have a buddy above level 70 to invite you and then leave. The mission is "Stocks and Scares" — thanks John Knight for noticing!
2. So start the mission and then call up Pegasus to get your tank.
3. Proceed into the warehouse and kill all the enemies inside.
4. Now, this is the important part, set up your tank so that the back of it is against the steel pillar (see the pic below). This is required because each time you fire off a round the recoil will move the tank back a bit. Also turn off vibration on your controller.
5. Now point your barrel at where the two enemies constantly spawn, tape down the fire trigger (L1 on PS3, LB on Xbox 360), and go away.

This will get you 100 reputation points every 8 seconds indefinitely...!

Thanks iambutternumber for the tip!