Spark plug OEM BMW or OEM Audi

Within the last 8,000 miles New spark plugs

I had similar problems with mine until I tried stock F80 M3 plugs. Mfg #12120039634KT1. Mine was 07 N54 FBO.

Check out getting rs3 spark plugs if it’ll work.

Guy was gunna charge me $720 USD for changing my serp belt and another $550 USD for changing just my spark plugs. That's $20 for the serpantine/drive belt, $150 for the belt tensioner and I think another like $120ish for spark plugs (B58 engine). So in total I saved myself roughly $1,000 just doing it myself.

Audi A3 spark plugs work like a charm. Stage 2+ & fully upgraded supporting hardware.

Since I've owned my 18 S4 i've done almost everything myself:

4 oil changes, spark plugs at 40k, 2 sets of pads and 1 set of rotors, both air filters.

I did track it extensively, probably 3-4,000 km of track use. The only thing it needs is brake fluid and better pads and you're good to go. My car was flawless for the entire time I had it. It threw a CEL right before I sold it that was solved with a simple spark plug change. It never overheated at the track and it was a lot of fun there and very refined and comfortable for highway travel.