Did you ever wonder what is behind this panel on the driver side firewall? Well, it provides access to the brake master cylinder, wiper motor and wiring harness. If you ever have to open it, be careful. If the access door breaks, you will have to buy an entire cowl piece!
Yes, I figured that one out, mine is getting a brake fluid change this winter when its sitting pretty in the garage. I just ordered, and got the adapter for my Motive brake bleeder pump.
You should check my post here: https://www.challengerforum.com/threads/brake-fluid.7283/#post-39347 I did a brake fluid change last year.