I need to get a spare key for my 03 sti, I have the sigma alarm that the actual key controls via the 1 button.

I got a second had key from eBay and a new blade but you have to destroy the fob to get the old blade out.

Does anyone know where to get these keys apart from the dealer, I see loads of used keys but no new units.

I'm sure the transponder from the second hand key I got can be programmed but need a good case and new blade in the fob.

cheers

I got a separate plain key cut and then cut the old one off after reprogramming fob so I have the key fob for opening and closing car and on the same keyring the key starts it and immobiliser starts car off fob hope that makes sense...😀

What you need do is buy another key with programmed transponder chip then remove transponder chip from new key & cut new key down to shank.

You then open up the replacement remote housing & dig out the transponder chip & get new programmed chip fit in housing. Once done cut the remotes key off but leaving about 15mm tail as use this to step lap new key to remote via small machine screws or 2 rivets .
Done this a few times to keep customers happy as way way way cheaper than dealer getting involved & better than remote separate to key . done neatly & key joint finished on mill or ground very precise it looks like it made like it originally.