When my dealer wanted to charge me $600 for a hitch and "tow package", I about laughed in his face. Later, they were far from helpful (and perhaps even dishonest) when I tried to get an after-market hitch installed, but I figured it out without them. Here's how you can do it. This applies to a 2002 RX300. Cost: roughly $150 and 2 hrs of my time.
1) Go to U-Haul and have them install a hitch compatible for the RX300. They have a model that is an exact fit -- it bolts into the holes already provided in the Lexus auto frame. Cost: about $130. Time: 40 min.2) Go to the web site
4) Under the vehicle, directly below the spare tire, you'll find a black plastic cover with three nuts holding it to the underside of the car. Remove the 3 nuts. This will expose a gray cable connector that the Draw-Tite #18245 connects to. Reattach the plastic cover and run the wiring harness/cable to the trailer hitch and secure it with zip-ties. Time: 20min
5) In the engine compartment, remove the fuse box cover. Look at the cover to determine where the 20-Amp fuse must be placed for the "TOW" option. Insert the 20A fuse (included in #18245). Time: 5 min.Viola! Done!
I hope this helps someone through the Lexus Dealership hassle I endured.
Thanks. dkar