Always a source for odd automotive accessories - J. C. Whitney.

http://www.jcwhitney.com/autoparts/P...015146/c-10101

Maybe a reverbarator would sound good on the radio? If you have to ask what a reverbarator is then you never drove a car before 1970. Edit - make that 1968. That's the last time I installed one - then FM stereo became available in Massachusetts.