Hi Cl
The key used for opening the trunk lock on my brothers GS300 wont work. Is this just the lock assembly that broke? Hard metal like that won't break that easy IDT...
Button works perfectly.

 

So I guess this hasn't happened to anybody before.

 

Sounds like the lock to me. Or maybe the trunk lid was swapped before and the original lock was not re-installed. You are using the same key as the ignition, correct? "The key used for opening the trunk lock" makes it sound like a second key.

Also your avatar is headache inducing.

 

Well, this Lexus use to be my G-ma's and when it was brand new somebody smashed into the back of her, so I think the trunk lid was replaced. But the key lock only stopped working this year, not 1999...thanks for the compliment on my avatar...home made!

 

You can try lubricating the lock with dry graphite powder. Does the key turn or not?

 

The key lock turns, says my brother. (his car) Will try lubricating the %^&*%^# outta it.