Maintenance/Warranty and rattling noise issue

[ZoroItaliano]

Hey guys I needed your advice on this.
Just to give you a bit of history I have a 2009 370z base that I bought brand new in 2010. The first oil change was free from the dealership. Then because they charge an arm and a leg, I decided to get my oil changes done by a gas station by my house, bringing my own oil and filters to the gas station. My car has 38k miles on it, I need to do my 30k still, but a little bit on the fence with who I should bring it to... dealership or local mechanics.

Also, I have this rattling noise described in more detail in this thread:

Rattling noise coming from front or front middle of 370z

I'm just trying to cover my butt on this for the future just in case I need something major done that warranty should cover. I only have 1 year left of payments for the z. I appreciate any advice you guys can give me. Thanks