After replacing the coils, plugs, and valve cover gaskets, I was finally able to drive the car. Drove it to an auto parts store to get a brake light bulb, everything was fine. Then I stopped at the post office, to drop off a couple of packages, and the car would not shift into Park. The lever would go all the way to the top, and even click into place so I could take the key out, but it was still in reverse. I backed into a parking space so the car wouldn't roll away (parking brake wasn't working either), dropped off the packages, drove home, and had the same problem, except the parking brake was working now. All the other gears are still in the right positions, neutral is still neutral, etc. Reverse is even still reverse, it just stays reverse all the way to the stop of the shifter travel. I'm thinking it's a shift linkage issue, or some kind of position sensor? I searched but only found threads about not being able to shift OUT of park. Any assistance would be appreciated, thanks. Vehicle is a 2006 Lincoln LS.