Do you really need three of them?
I checked on my Challenger and there was only one in the middle, in both panels. I bought one and placed it in the front of my right panel and I couldn't get it in, no matter how much strength I put on. Then I watched the two panels and it occurred to me that the front and back slots where the clips go were untouched (except for the right front slot which I tried to install the clip). Shouldn't there be any signs of a used clip that was removed ?
Then I saw that the front and back slot were exact fit for the door chassis. I installed them and left them as they are and there are holding nice...