wiring motor with cruise switch

So I have a 1991 toyota mr2 and currently have a simple 2 wire gear head motor that runs forward and reverse via a DPDT switch. I would like to ditch the DPDT switch and use the factory cruise control switch to control the motor. I'm sure there are more than one way to do this, I prefer the simplest and least amount of parts. Unfortunately I'm not too familiar with DPDT relays and if they operate similarly to the switches. Diagrams would help greatly thank you in advance btw this is to activate the gearhead motor for the exhaust cut outs