A Very High Slope
You can see by this picture that the owners of this home have been parking their cars on the side of the road because who on Earth would want to drive up a slope that steep just to park their car in the garage? Just think of the dangers that could come from attempting to do so!
Once you finally get your car into the garage, all you would have to look forward to is the danger of getting your car out of the garage the next time you need it. Hopefully, you have an emergency brake, but regardless, you will still have gravity working against you.