So, one of the cases on a master key cracked. I have the metal key part, which will start the car, etc., if my fingers are strong enough to turn the key part in the ignition.

But, when looking at the entire construction of this "valuable" part, it seems like the laser key, which has the transponder it, ought to be able to be inserted/pressed into another key fob body and held secure with the small set screw.

Am I wrong?

Why can't you buy just a plastic body? Rest of the parts (laser key, remote button module, etc., could just be dropped into the replacement.

Is this too simple?

The keys break as well as being lost.

 

In my opinion it is that simple. I've replaced many car alarm remote bodies and just swapped the guts into the new case. It is just a matter if Lexus/Toyota want's to sell the case alone or not. They could easily make that part available; however, they make more money if they get to charge you for an entire new transponder key and reprogramming.

 

I have 2 keys that the case is also broken. I bought a key on ebay for 10 bucks and thought it was as simple as taking the metal key and remote but it is more complicated than that. The case has the metal key attached to it. there is no way to remove the metal key from the case. So what I did was dremmel the top part that supports the metal key and then push the key through the opening and then replace the key with the key for my vehicle. The structure is still strong but may have been weakend a little. If you want pictures of this email me and i will try to post it. or I will send you the image.

 

Not sure this will work in the RX330. There is a transponder in the key that enables the ignition immobilzer. The wallet key is in a plastic holder that must be held against the ignition tio start the car. No plastic holder, no start.