Best Toyota Service in Sacramento

Hi, I am wondering what other people's experience with Toyota service
departments in Sacramento. I have a 2005 Tundra DoubleCab and I was
told by my service advisor that I had coolant in my sparkplugs and they
don't know why or have no idea why. After checking around, and talking
to some collegues they all seem to thing it is more than likely a blown
head gasket. When I talked to Maita Toyota (who I bought it from) they
said they have no idea and they don't think its a head gasket, but they
could not offer any explaination as to how the coolant got there. My
truck is still in warranty, but I think Maita just doesn't want to find
the problem and fix it. So my question to everyone is, who do you think
the best Toyota service department is, Maita, Folsom, Roseville?