As in gently push it in/let it out constantly while you're giving it gas.
For instance.
[1] Put full brake on with your left foot
[2] Tap her into autostick, 1st gear
[3] Slowly give it gas with your right foot
[4] Just as the RPMs start to rise, with your left slowly rock the brake pedal in/out (while still constantly keeping enough brake pressure to prevent your car from moving)
[5] Continue to bring the RPMs up while continuing to rock the brake pedal slightly, and you should be doing a big ol' burnout for as long as you want (you must continue to 'rock' the brake pedal slightly for the duration of the burnout)
I don't have first hand experience, but that's what I read on this article:
2008 Dodge Challenger SRT8 Full Test
Originally Posted by The Article
Tricky Business
And yes, we finally do some burnouts in the Willow Springs area. Doing a burnout in this car is somewhat tricky. You can't just mash on the brake with your left foot, feed throttle with your right until the tires start spinning, then floor it and go. That worked in the original '70 Challenger. Forget about it in 2008. The culprit is modern technology.
But you can do it. First you have to shut off the ESP, which itself is a two-step process. Hit the dash button once and you get a "soft" shut-off, which means it's still kind of on. Then hold the button for 5 seconds and it's off — kind of. Yes, it's off but it will still intervene in certain circumstances.
For 2010, the federal government has mandated certain ESP interventions on all cars regardless of whether the system is off or on. Since the engineers were designing a new system for this car anyway, they dialed in the compliance for the 2010 regs. So for instance, if you mash on the brake pedal with your left foot and open the throttle with your right foot at a steady setting for 2 seconds or longer, the ESP computer interprets that as the car being "in distress" and shuts down the engine.
Big Brother Takes the Wheel
To do a really major burnout, you have to trick the electronic brain and slightly modulate your foot on the brake as you spin up the rear tires. (Modulating the throttle doesn't work as well.) The computer interprets this modulation as the driver having fun, and it's actually programmed to allow for fun. Then you'll have your burnout.
By the way, when you release the brake, don't let the revs hit the rev limiter at 6,200 rpm or the computer will shut down the engine, shift you into 2nd gear, then give you back control.
It's all a bit tricky but once you get the hang of it, you can smoke the tires at will and look like a NASCAR hero after a big win.