Hello.
DO NOT PAY the dealer anything. I did the following:
Bought a used Lexus remote key from ebay for £15 all in
Bought a new un cut lexus key fob from ebay for £10.75 all in
I took the remote control unit from the used key and put it in the blank key fob.
I then took this to the local locksmiths who cut the new key for me from my existing valet key. Thats cost £5.
All the doors and boot and glove box work from this newly cut key.
I am now going to programme the new key to my IS200 using the simple instructions available on here and and on myIS.
"Basically, every lexus key has two functions: start the engine(immobilizer) and remote control (lock unlock doors, activate/deactivate alarm)
To program the immobilizer bit of your new key:
First, have your new key cut. Then:
For 1998+ Toyota, Lexus
Add Duplicate Key
1. Simultaneously depress and release brake and accelerator pedals 1 time.
2. Insert existing master key into ignition.
3. Within 15 seconds depress and release accelerator pedal 5 times.
4. Within 20 seconds depress and release the brake pedal 6 times and
remove key.
5. Within 10 seconds insert new key into ignition.
6. Within 10 seconds depress and release the accelerator pedal 1 time.
7. After 80 seconds new key is registered and security light goes off.
8. Remove new key and depress and release brake pedal 1 time.
To make your Lexus remember your key's wireless signal:
For the remote part in drivers seat WITH DOOR OPEN.
Start with door unlocked.
1. Put master key in ignition, turn to on, then back off and remove.
2. Using the lock/unlock button on drivers door. press lock.. then unlock 5 times.(lock,unlock,lock,unlock,lock,unlock,lock,un lock,lock,unlock)
3. Close drivers door, open drivers door.
4. Perform lock/unlock procedure again. DO NOT close and open drivers door. Just the lock/unlock procedure again.
5. Insert NEW key in to ignition and turn to on, then back off and remove.(at this point the doors should lock and unlock by themselves ONCE)
6. Now press both lock and unlock buttons on REMOTE. Release after about 1.5 seconds.
7. Now press just the lock button on remote.
once you press the lock button, the car should lock and unlock ONCE, if it lock unlocked TWICE you messed up somewhere.
8. Now open and close the drivers door a couple times to close programming.
if you did it right, remote will now work."
Hope this helps save £1500!