I painfully came up with a list of all Lexus Dealerships in the US. This post contains the original data in tab-delimited format. This POI is already uploaded into TomTom so you can grab the POIs from TomTom home. It has the addresses and GPS coordinates in this file in case you need either one or both for your own GPS device.
Hope this is helpful to others.
Lexus_Dealer_List.txt