I'm getting close to 100K and considering that this car is 16 years old and I don't know much about maintenance done before I bought it, I don't want to wait since I will have a number of long distance trips. My dealer let me down and I'm still a bit mad at them and am considering taking it to a mechanic who has done good work on our non-chryslers. The key question is what spark plugs work well with these 3.5Ls and which ones should I avoid. I believe that these came with Platinum plugs from the factory. Is this correct? What would be a good quality one?

 

I would stick with whatever the direct OEM replacement is. Autoparts store should be able to tell you. Any decent mechanic can replace spark plugs, no need to take it to the dealer if you cannot do it yourself.