Does anyone know where this relay is, if there actually is one? Wiper motor replaced, switch checks out OK, but wipers still work erratically.

Your owner's manual will show the location of the wiper relay if there is one - probably is.
Would guess, under the hood on the left side.
The fuse holder cover may also list the location.

I found out from the dealer that there is only a relay for the rear wiper on a wagon. There is no relay for the front wipers. (Guess that's why I couldn't find it). Thanks for the help anyway.