The #1 team has never really been able to run with the lead pack at restrictor plates. I think there are several factors to consider.
First of all, the #1 team is the least funded of the three DEI cars. Jr's team gets about 50 million, MW about 25 million, and Park's team about 12 million. Even though they are all a part of the same team, I don't think each team has the equal amount of resources to work with.
Second of all, I think the driver is a part of the blame. I'm not quite sure Park is 100% right now, but he has never really ran well at the superspeedways anyway.
I think the team chemistry isn't there right now. Jr's team is as close as family (some of them are family), MW's team has really turned around with Slugger, but Park's team has recently lost their crew chief. The team is looking for direction right now, and I'm not sure Park is going to be able to help them.
We'll have to see, but unless there are some major improvements, I don't see Park being in that car for next year. The team needs a change right now, and so far it has changed crew chiefs. Next up is a driver change. Even though I like Park, I have a feeling it would be better for him and the team if he moved on.