Same Problem Here But The Fix Was Quick
I had the same problem the first day I had the car. I took it back to the dealership, the next day, and they made some quick adjustments and I haven't had a problem with shifting into reverve since them. It also felt tighter after they made the adjustments, so it obviously was loose. I don't remember what they did exactly but it was just a matter of getting the car up a lift and tightening something. I watched as they did the work and what ever the problem was it was the first thing they looked at. So it shouldn't be hard for dealer to adjust it. Hopefully they fix it as you wait and not take all day to look at it.
Good Luck
2003-300A
Trilogy #8 with Custom Pulley Produces 12.4psi of Boost
407 RWHP and 384 RWT
Best 1/4 Mile 12.028 @ 117.01mph
From Lidio: Trilogy #8 install & Custom Tune, Custom Pulley, Chip, Accufab Throttle Body, Baer Claw Front Calipers with Crossdrilled & Slotted Rotors All Around, Custom 2¼ X-Pipe, 3 Chamber Flomaster Mufflers, Widened Rear Rims with 305 Nitto NT-555R Extreme Drag Radials, Auburn High Performance Posi.
From Reinhart: 4.10 Rear Gear, 180 Degree Thermostat, Motorcraft Plugs, Metal Matrix Driveshaft, Rear Sway Bar.
From Metco: Carbon Fiber Intake Tube, Control Arms & Watts Link.
From Others: Kenny Brown Braided Brake Lines & Dead Pedal