Hey all, my 03 A4 is approaching 50k, I want to change the plugs because I'm not sure when they were done last, engine runs ridiculous smooth, but still would like to change them, along with possibly coil packs, I was just going to do the plugs, do you suggest also doing the packs this early with only 50k? As for the plugs, I was going to get the NKG platinums, but whats the deal with the iridium's?