I had only Champion Platinums in my '99 Neon R/T the entire time I owned it, 3 years+, and it ran flawless. I hear people always ragging on Champion spark plugs, yet I have always used them from the $.99 cheapies to the Platinums without any problems what so ever. I have tried many other brands from Bosh to Accel U-groove to Splitfires and I have yet to see any improvement in performance, so I'll stick with my good ol' Champions, that has always been Mopars plug of choice and it is mine as well. And yes I am aware that more recently they have also used Bosch and NGK, but they have always used Champions.
I think the greater problem in the ignition system is the sad plug wires, they have between 1,500-3,200 ohms resistance and they're not even a foot long. Everyone that has the 2.0L DOHC or the 2.4L DOHC need to switch them over to MSD Super Conductor plug wires, they smooth out the idle, they actually give it a stronger meaner sounding exhaust (most don't believe this until they get them and then they are shocked that they could make that kind of a difference) and increase horsepower and fuel mileage. They have less than 50 ohms per foot of resistance and since none of the plug wires are even that long, they are between 20-40 ohms resistance which is thousands of times better than stock.
Combining the MSD Super Conductor plug wires with a set of Champion Platinum spark plugs is a great and flawless combo. I know this for a fact since I've ran this combo in my '99 R/T for the 3+ years I owned it and now with my '04 SRT-4 and they are both still running great. In fact, my '99 R/T with the MSD wires and Champion plugs also had/has the Mopar Performance CAI, cat-back exhaust, chrome header, motor mounts, bobble strut and PCM (computer) as well as front strut tower brace, MSD coil and REX motor mount inserts on it and with a few drag runs mixed with in town and freeway driving averaged 35+ MPG. My SRT-4 with the MSD wires and Champion plugs also had the Mopar Performance cat-back exhaust, STS and BOV as well as K & N Typhoon CAI, MSD coil, 2 OCC's, Prothane race motor mount inserts and front and rear strut tower braces on it and with the same type driving as the R/T, with the exception of more spirited driving, it got 21.9 MPG the one time I checked it. It would get better if I could keep from enjoying the turbo, but it now has the Mopar Performance Stage 1 on it too.
