I almost can't resist.

We have 'rain glass' pattern in the bathroom window - you can't see anything. I think it would be fine for your garage.

Be sure you check it in person - I had rain glass in a bathroom closet and the contents were not completely obscured.

I got my glass garage door from bp, you can definitely not see in, I am very private with my garage :)

Here is a link that might be useful: bp doors