Mike:
Agreed the newer cars have electronic engine controls but all gasoline fueled cars still have an ignition coil or a set of ignition coil "packs" that could be used as a source of high voltage if a suitable driver circuit were used.
Another source for high voltage thats easily obtainable would be a "fly transformer" out of an old CRT television set. Also the power supply out of an electrostatic air cleaner would be a good source of high voltage D.C..
A.D
