I suggest making 5 beforehand. At a fireside meeting, Gale will hint at the project so you are warned when it comes. You'll need in total:
-5 small engines (Abandoned ruins #1, Hazardous ruins level 1)
-15 rubber tires
-25 copper bars
-10 single seats
-30 fiber cloth (worn fur dropped by most furry creatures or get the civil corps to find at the cost of some money)
-25 glass