Anyone know the exact size bit to use? I've looked online and seen mixed opinions on the exact size. Would like to get a good idea before I start drilling into my dash.

 

I'm told it's 3/4"
I have their reverse lights sitting in my garage right now pending install. I'm going to start small and work my way up. Might be the right time to invest in a step-up bit...but they are pricey!!

 

Just use a step drill bit. then you can start small and continue upwards