The factory cap for the windshield washer fluid reservoir is flimsy. This cap should outlast the vehicle if you printer produces a dense part without voids. I made it a little loose fitting because it has a hole for a lanyard to keep from losing it. Better than breaking the cap or getting it stuck on. Could scale the whole part just a bit to make it fit tighter without changing any critical dimensions. i made the cap fit tighter, a little thicker and added a few more fillets to increase strength. it is quite a lot better now.printed it on my Solidoodle III using a .2 mm layer. don't recommend a Solidoodle, they are terrible without major modifications as mine has received.