I called Lexus today, working with Automotivetouchup.com, as I bought a paint that "might" work; Item No.: HBTL-BC
Description: 1/2 oz Touchup Bottle, 1998 Audi All Models: Alusilber Metallic/Aluminum Silver Metallic 9945
Item Price: $9.95
Item Total: $9.95
Lexus called a dealer (really? They don't know the answer?). The dealer said, "There is no paint number for the wheels. We either take it to a body shop or replace the wheel entirely."
Like I said, this is a really good business opportunity. Wheel touch up paint.