There's a lot of coil threads on the forums if you searched. I changed mine recently, about 4K miles ago; At 30K. I guess the stock ones suck. I bought mine from AAP (Advance Auto Parts) for $84 I believe plus shipping. They're awesome. Plus, I think they have a lifetime warranty. There's a thread somewhere in here that had some discount codes for AAP. I got like 20% off my purchase I think.