I recently had a similar problem. I was told, first of all, that the door speakers are not 6x9, so you cannot buy aftermarket. Instead, they are a special size, forcing you to buy Lexus speakers. Not sure if this is true, but I have had several people tell me this. Are you sure that the speakers are blown? Are they just "rattling"? I found out that my car had deteriorated speaker brackets, which caused a rattling, although the sound was good at low volume. I had a speaker shop, familiar with this problem, rebuild the bracket and solved my problem.
