Plastic underbody shield?
 

Just got mine in dec, noticed it had a cracked lip when i bought it. Turns out the entire underbody shield is janked to all hell, and today it fell down and was grinding on the pavement. So i pull out four different types of bolts the PO had used to jerry rig it together, and now i'm stuck with a broken piece.

cheapest I've found was
http://www.mazmart.com/ItemDetail.aspx?id=312
which is still an exorbitant price. Anyone got one for cheaper, or know where I can get one?

partsgroup.com

really nice guys, cheap OEM parts.

Lots of authorized Mazda dealers selling discounted parts online. Search Google under genuine Mazda parts. A lot of them use the trademotion interface. Shipping prices vary, some free over certain amounts. Take notes while you search.

Junk yard is your friend.

Also part outs in the for sale section.