I'll run through some steps as i see them;
1) Buy a second hand key
2) Buy a blank blade and get it cut at a locksmith
3) Get a blank chip
4) Buy
MultiECUscan
5) Use
MultiECUscan to code the new chip
I might try it one day, but its a lot of bother for a spare key
I haven't looked on ebay but it seems logical that someone there will sell a kit comprising an old key, blank chip and blank blade so the steps could reduce to;
1) Buy a spare key "kit", that includes an old key, a blank blade and a blank chip
2) Get the blade cut at a locksmith
3) Buy
MultiECUscan
4) Use to
MultiECUscan to code the chip and create a new key
Mmmm, i might try it one day, but can well imagine having to send for an auto-electrician to get me out of a fix lol