I didn't mod or tune up for my car. I'm planning to keep them as a stock. anybody knows which spark plugs I have to get?

Please advise.

Thanks

 

Pick up a set of NGK BKR7EQUP. They are the same plugs they use in the JCW....one step colder than stock. They don't hurt anything if you run them in a stock S, and if you ever put a pulley on your car and up the boost, you won't have to change them out. They are good to go!

 

If it is stock with the stock supercharger pulley these are the correct ones
https://www.waymotorworks.com/r53-st...gs-by-ngk.html

If you have an aftermarket pulley or going to add one this is what you would use
https://www.waymotorworks.com/john-c...gs-by-ngk.html