Gareth
i had a similar prob when i bought my is200 a few weeks ago
the owner only had one key, which was stucktogether with superglue........
bought a good quality blank key £15 from fleabay
went to a local key cutter, told him i wanted the blade cut to match
my cruddy original.they ask where you got it from,as they do a better quality
one! for (in my case £45.no thank you), tell them you got it from lexus!
he then cut it for £15,going on and on about it may not work, theirs is better
blah blah......
then carefully open and remove case get at transponder,(i had to very careful
as the superglue had worked its way into the case as well...
then just swap it over to your new case,and bobs your auntie
£30 is a lot better than, sit down while i tell you the price from mr lexus!!!!!!
regards johnboy