Ramyond

So I've been servicing my rx8 at a local mazda dealership, but i'm kind of doubting their knowledge on the 8 and everytime I get my car service...I get my car back with interior scratch marks that I do not notice untl the next day...
So do you guys know any reliable rotary auto mechanics around Irvine or Monterey Park? and also...if I do get my car serviced at places other than the delearship....would mazda possibly void my warrantee because there's no "dealership record" of oil change/services? oh...and um...are the service charges compared to dealership or more/less?
Sorry this is mouth full of questions!

Thank you !!