lost a Mazda MPV key
 

Hi, I lost of a Mazda MPV key (2005 - with a chip), and I'd like to avoid paying $140 for a new one. I understand from the threads here that there's a method to program a new key myself (though I'd still have to order a key and get it cut). None of the threads have specifically addressed the MPV in particular, looks like it's more common with the 3, so I'm wondering if anyone had experience with programming a key for the MPV. Also, we still have one key that works...Is there a chance that I'll mess up that key and won't be able to drive the Mazda with either one?

Any help would be greatly appreciated. I'm a new DIY-er and, while eager to learn, I don't have much of my own experience to fall back on, and I hope I can figure it out with help from users who've already done similar projects.

Thanks!

David