Caspers Hi-Speed Fan Kits work great and are well made. I have installed several on Regals. You can install a relay in parallel with the manual switch and activate the relay with a thermal switch. Use the thermal switch to supply a ground to the relay and find an ignition on hot wire to provide a positive source to the relay. To tap in to the wires going to manual switch, fold the wire in half and burn the insulation off, twist the bare wire and solder to the correct wire going to the relay. Don't forget to put a piece of loose heat shrink on the wire before soldering. I install a Honda K swap hose adapter in the upper radiator hose and use a late 90's Honda Civic style thermal fan switch. Mounting the manual fan switch under hood makes for an easy way to test the fan motors periodically to make sure they are working ok and aren't too loud. This set up works well with a 180 stat, I don't think it would work with a 195. These Civic fan switches make at ~ 200F.
