How do I find missing parts for the truck?

The Ole’ Rust Bucket quest is available as soon as you complete the First Recipes quest. It asks you to find missing parts for the old truck (4 wheels and 1 headlight). These are scattered all over your farm and you can dig them up by harvesting your crops as usual.

When you see a part, click on it.

After you find all the missing items, install them by clicking on each part in the Auto Repair Shop.