Car started holding at 2000 rpm on its own. Turned it off and the smoke was coming from under the hood. Looks to be drivers side firewall area. Smells like the kind of burning plastic that will sting your eyes
Just drove it again and it ran fine till it got hot again.
Is something leaking (oil) onto your exhaust? Have you had the chance to verify if any fluids are leaking at seals near the back of the motor?