Audi Quattro Lithophane

Pretty easy and nice to make, good idea for a gift.

Just a quick search on the internet, and you'll find websites to upload your pictures, and download the STL.

Layer height was 0.12mm, be sure to select 100% infill (or 999999 bottom layers), and don't print to fast. 

Maybe use a brim or even a raft, since print must be done in vertical position.