ConnecTank

You obtain tank parts by defeating them each time in battle, each tank have 5 parts. You can navigate your map, hover over the tanks and see how many parts you have left to get.

After a few gigs, on the main menu, you will have the option of paying 200 coins to get a 100% chance of gaining a tank part after each gig you do. One of mods you can get is a pirates hat, which will give you 2 parts instead of one. One tank which has this mod from the start is “Mic Dropper”.