I'd say about 90% of the time I can start my car, push in the brake and shift into Drive. The other 10% I start my car, push in the brake, and can't shift into Drive. Does anyone know what could be causing this problem?

 

it's probably the switch behind your brake pedal that allows you to switch into gear, I've seen people have issues with it sticking over the years

 

Thanks, I'll take a look during lunch and see if I can see something.