I got inspired by Ana to design my own toy garage - so that there would be somewhere to store all the hot wheels that kept piling up! I have no idea what the angle is for the driveway ramp - it was trial and error with help from my husband, but it's pretty sturdy. Between the mitered cut and the copious amounts of glue, it holds the weight of a 25 lb toddler walking up it (though I try to discourage it!).
I used chalkboard paint and acrylics - so that we can draw parking stalls, lanes, or arrows as desired - my son helped with the painting. So far, the favorite activities are sending the cars down the ramp, one after another...

Estimated Time Investment
Weekend Project (10-20 Hours)
Recommended Skill Level