Sonic burger under the seat?

 

it could also be left over oil on a manifold from the work and it is burning off. Check under the truncklid where the pentosin reservoir is. If it is wet on the cap, then it may be a pentosin issue, accumulator or part of the system. Pentosin is not only flammable but corrosive. It will degrade rubber and plastic real bad. Also if your accumulator is going bad, you may feel a gritty type of clutch. But check for leaks before you start the car again. lift it up and go under it, check for wetness in back.