I just finished registered my GS300 yesterday. Stumbled upon the link where you can order your owner manual from Lexus from FREE.
Step 1: Type in the URL "www.lexus.com"
Step 2: Click on the "Owner" link
Step 3: If you are a registered owner, login. Or else you will need your VIN# to complete this step.
Step 4: After login, click on "My Lexus",
Step 5: Click "Owner's Manual", Scroll down to the bottom of this page to see "Order Owner Manual"
Step 6 : Click "Order Owner Manual", choose the vehicle you have registered with Lexus. See picture below
Step 7: Click "Submit" your order
The Best thing in life is FREE!