1.8GTI airbox mounts, am I missing something?

My air filter housing was shaking around like it wasn't on it's mounts and when I took it all apart I thought it had just come unclipped on the spring clip underneath. I reassembled it all but it was wobbly and the clip underneath wasn't really doing anything. There is no rubber washer like the two side mounts have and I can't find anything online. Is there supposed to be something there? I have found that placing a 20mm rubber grommet helps. 
Here's a picture with the bits circled in red.
Thanks.

Mine is exactly the same, no grommet or washer, but it doesn't move or rattle. Could your spring clip be distorted or stretched?

The lower ones can be a bear to get snapped in place correctly.  not a lot of room for large fingered folks.

On  side note, your Groundy cable has seen bettter days you might think about replacing it. Battery to frame and frame to enginetranny.