my smooth model has strange bumps I really have no idea why there are these bumps in the robot's chest

It doesnt look like there should be any in wireframe

But they show up in renders and solid mode

Also the customer said that the robot looks a bit too plastic and I should make him more fun. I gave him a shadeless freestyle version and said that he didnt like it, any ideas on how I can improve this model?
http://pasteall.org/blend/index.php?id=50764

UPDATE: Don't be an idio and just use edge split. Honestly, shouldve tried it sooner
Dont be an idiot like me and try using edge split in the modifiers tab. I remember having this problem before and it's caused by booleans and I fixed it many times before with edge split, so I have no idea how I was dumb enough to not think of that. Don't drink and model, kids, that never goes well