so on my 850 wagon the front shocks (driverside is worse) makes a clunk noise over bumps.
Its not a metal/metal sound, but is is very loud.
The top of the shocks "squeeks" alittle when you push down on the fender. Its not very loud, but then the movement isnt nearly as much as when you hit a bump.

After some online searching, I think it is the spring seat...the rubber bushing.

The price of these isnt bad, but I want to know if the bearing/metal plate part could also make the sound?

I took some pics.
One thing I read said that if the top of the shock (visable from under hood) can be seen moving 3-5mm that its likely that the "the rubber bushing around the metal spacer sleave breaks away and gives the strut assembly some 5cm of travel before the shock absorber will do anything"

I took a pic with the car on the ground...
then I jacked up that side and then let the car back down slowly and took a second pic.
Notice the black ring on the shock looks 5-6mm higher?

 

Turn the 21mm nut on top. If you can turn it, the seat is busted.

 

Just checked, I can turn it in either direction with ease.
I thought the seat was just the rubber bushing thing. How does that nut bolt to it?
Just to make sure Im thinking of the right part, this is what needs to be replaced, right?:
Volvo Suspension Strut Mount Spring Seat Sachs 87-439-A | FCP Euro

 

It turns all the way around? If so, its shot. That is the correct part.

When everything is in tact, the nut holds it all together tightly. When the seat is damaged, it allows everything to turn in the seat.

 

Maybe this will make it a little clearer

 

If it's making a noise vertically like yours is then it's more likely the spring seat that's failed/failing.
If it makes noise turning, then it would be more likely to be the top mount. It's sometimes called the bearing plate depending on who you're talking to
If possible $$, I'd do both parts as it's a bit of work taking it out, pulling it apart and then reassembling and installing only to have one of the mounts start squeaking in a month or six.
It would be smart to have it aligned after you get it all back together to make sure it's where it should be. That, or keep a close eye on tire wear and if it starts to look odd you know you need one.

 

Get the Volvo XC90 spring seats. Much tougher,fit just fine and last longer.