Bob, the car enthusiasts, or lack of, didn't put Sonics out of business. They've closed up 90% of their locations for some reason or another (economy, overall poor business?). I used to like eating there, but there are 3 or 4 in Lakeland that are gone, and many others in Hillsborough County.
As a bit of an update, There is a Sonics on Dale Mabry across from Kuhn VW, and another one on Bearss Ave.
There is also one in Clearwater, where hot rodders sometimes meet.