If you've got a 'clean up' sofware package on your PC for transfering vinyl records to CD, you can sample sounds off the web. Like the Tardis, or the 'Hooter'.
Rig up some 'all weather' external speakers under your car bonnet.
When I was a lad back in the seventies, I had a tape of a Top Fueller Idling.
Much fun was had down Solihull High Street, with the noise going thru a graphic equaliser - remember them?
It was a 'coke bottle' Cortina 2000 GXL. Mags, Metalic Violet with a white vinyl roof.