They're not a direct replacement and there is some modification needed to make them fit.
The stock coils are fine but because of the coil cover they tend to overheat and overtime this causes them to fail, I had a similar issue and ended up buying some splitfires as I couldn't find any stock ones for sale at a reasonable price. (or find any second hand)
I also wasn't willing to trust any of the other brands that make them (unbranded, ebay specials etc)
Turns out the coils were not my problem but they are a common fault on the S15.
I've still got my stock ones that are in full working order, if you're interested, drop me a PM otherwise I'd go with some splitfire