On a s5.

Dad removed the door panels years ago, lost most of the screws so their loose.

My friend removed my seats while I was sleeping, he ended up finding a few grams of mary jane bastard bent the brackets and didn't put in some of the bolts, I found all except I think one per seats.

The part of the dash that goes on the pass side, covers the speaker, dad lost all of the screws.

What do I need for the above, and where can I get them?

 

look in a junkyard or for someone parting out their car in the classifieds.

 

Local fastener store...

 

A)Get new friends
B)Go to Fastner supply

 

I've used both the local hardware store and McMasterCarr. McMasterCarr has a wide select of fasteners with various materials. I use stainless on all non-structural applications (electrical grounds, lightweight items, etc).

 

Invest in a parts car. Sometimes it saves a lot of money taking this route...

For random nuts and bolts, visit your hometown hardware store. They usually have more metric fasteners than the big chains (lowes, home depot) tend to stock. If your aren't in a hurry, order them through your mazda dealer. They don't charge shipping unless you need it rushed. I ordered a few bolts from the dealer for my rear hubs when I replaced my wheel bearings and rear steer bushings last year