Retro-fit factory cruise control kits for cars before they were pretty much standard.

Got one once for an e36 325i on e-bay from Hong Kong, BNIB, for stg£50. The twin 325i that followed it I would have loved to have had another kit to fit to it but never came across a bargain like it again.

Have also retro-fitted it to an e46 328i Touring and had an e30 325i with an aftermarket cruise control kit fitted. Might do it for the Z4 at some stage. It seems to be a rare enough option fitted to these.