Nice summary of the steps to take in an emergency with your LS460. This is from the Lexus owners site.

I didnt know there was access to the emergency brake from the trunk with a tool provided under the spare..or that the door handle needs to have the inner part popped off so you can use your mechanical key, there are some interesting tidbits you may find of value also. Nice to know some of this before you may have to use it. It would be priceless in 911 situations.