Using car switch for Arduino input

Thanks! It's an experiment vehicle so its primary purpose is to serve as my playground, rolling on the road is not on the priority list :smiley:

Is there any rules or best practices I should know when it comes to pullup? A lot of people use the 10K resistors for pulldown, but then again there are pullup internally available on most Arduinos....so is there a purpose when to opt for internal vs. external resistors?