I have a rotation loop, but I want it to end it before my animation ends.  I have a tire rotating on a car, and when the car reaches the end of the motion path, I want to have the tires stop their rotation, and the car sit there for a few seconds.

Did you give up on the EZcarRig? That should do this for you. Though I havn’t yet used it in production, havn’t had to do any car anims since I found it.
In the past doing cars on paths, I would Parameter Wire the wheel rotation to the % along the path of the car, to sync the rotation to the movement. The trick with this was to get the maths right in the param wiring so they rotate at a realistic rate on the ground, not spinning or sliding.

I had to give up on the ez rig because I was having all sorts of complications with scale, etc. and didn’t have time to trouble shoot.  I will have to look at the plugin again once I’m done with my deadline.