Omar's Discount Tire and Auto Repair in Union City (just over the edge of the JC Heights border) has been pretty straight-up with me over the years. Despite the name they do more than tires. Great Yelp reviews, which is what made me go there in the first place (and seemed pretty unusual for car mechanics around here!). They've always been very straight-up about costs, very straight-up about what they can and can't do, very good about giving advice on things (including in way that doesn't make them money in the short term). You can call them and a real human will answer the phone and answer questions. Only downside (for me, YMMV) is they always keep Fox News blasting in the little office (sigh). We use them for anything that we don't want to take to the dealer (oil changes, tires, checking out potential problems, etc.) because the dealer always charges an arm and a leg even if they don't do anything.