This is my picture. Lots of fun in the making. It is a 30 second exposure and is done by having a Tesla coil on top of the car. A long rod from the top curves down nearly to the ground and sparks jump the remaining 1-2 feet. Now if the rod is rotated, and a long exposure is taken, there will be a ring of sparks.
This is not double exposed or altered in any other way.
My son was apprehensive about getting into the car, but it is quite safe inside.