Ah, cool. I went ahead and soldered my vss connection like the injection connection, then blobbed some blue rtv in/around the solder joint. I also started with the wrong wire, shoulda used Speedometer output instead of the vss
The thing is, the saturn doesn't have a speedometer cable, it has a hall effect thingie that sends the driveshaft rotation signal to the ecu, I was tapped into that (wrong). The ecu then generates a pulsed signal to the speedo (right).
On other cars, it may be that the speedometer IS connected via a speedometer cable and has a little switch in it that sends the distance info to the ecu.