The cracked one on the left is on four cyl. cars only.
The one above should get lost if you have a radio.
The rectangular one helps a warning lamp work.
The four on the right are shown front and back.
The round one seals an 'emergency' hole.
The one on the right is not found on 'plain Jane' cars.
Where do they go ?

One ones on the right look like old cookies. I'd say they were destined for the driver's mouth.

Is that rectangular one part of the E brake system? Cause if it is, i forgot to put it back on my car. Couldn’t figure out where it sits. Is it a ground contact? Hmmmm

You're on the right track Dion

Ooops