Automakers continue to invent ways for cars to do more - from traction control to cameras - and some can even park themselves. Unfortunately, they can't repair themselves. When you need repairs or maintenance, a good auto repair shop can minimize the hassle. A bad one can create new headaches.

Delaware Valley Consumers' Checkbook's evaluations of 428 area shops for quality and price distinguish the good shops from the not-so-good ones. Its ratings are based on more than 10,000 reviews by area consumers, consumer agency complaints, more than 1,600 price checks by its mystery shoppers, and other sources.

Fortunately, there are a lot of top-quality auto repair shops in the area. Checkbook found that 144 of the shops were rated "superior" overall by more than 90 percent of their surveyed customers.

But there are plenty of shops to steer clear of: Sixty-one got such favorable ratings from fewer than 60 percent of their surveyed customers.

Checkbook's mystery shoppers also found dramatic price differences. For example, to replace the water pump in a 2007 Toyota Camry, prices quoted by shops ranged from $448 to $1,435. To replace the starter motor in a 2007 Ford Fusion, prices ranged from $291 to $567. Hourly labor rates ranged from $50 to $139.

Checkbook's ratings of area shops include a separate rating for price, derived from price quotes collected by its mystery shoppers for specific repair jobs. You want to be sure a shop charges fair prices before you go there because, like most repair work, it is hard to shop for price before you know exactly what needs to be done.

If you know what repairs you need, you can compare prices by calling a handful of shops for quotes. Checkbook's shoppers found it was surprisingly easy to get price quotes from auto repair shops over the phone.

If you don't know what work is needed, call one or more shops and describe the symptoms: what the car is doing or not doing. Shops might be able to tell you what's likely to be wrong and quote a price. If so, get quotes from several shops.

When shops can't determine what's wrong with your car based on your description, you'll have to take it in for a diagnosis and estimate. Then, with estimate in hand - and assuming the diagnosis is correct - check with competitors to see if the shop's price is fair.

You don't have to pay more for good service: Checkbook found no relationship between the prices shops charge and their quality.

Don't assume dealerships offer better expertise and service. In fact, Checkbook found that the opposite is true: On average, shops run by non-dealers were far more likely to satisfy customers than dealerships and offered far lower prices. The non-dealers were rated "superior" overall by an average of 86 percent of their surveyed customers compared with only 67 percent for dealers. Prices at non-dealers averaged about nine percent lower. Checkbook's advice: If the work you need is not covered by a new-car warranty, use an independent shop.

With any shop, communication is critical. Checkbook advises:

Give the shop a detailed written description of your car's symptoms. But distinguish between what you know and what you think you know. Don't guess. If you mention a specific repair - say, repair of the water pump - the shop may check or even replace the water pump and then go on to fix what is wrong (possibly worn-out alternator bearings).

If possible, speak with the repair technician who will work on your car. Service write-up personnel at large shops often know little about car repair, and those who do may not be able to describe your car's symptoms to a technician as well as you can.

Either get a written estimate in advance or write on the repair ticket that no work is to be done without your approval based on a written estimate.

Get a written, dated invoice that details parts, labor, and the vehicle's odometer reading.

Pay by credit card. Doing so gives customers enormous leverage by letting them request charge-backs if something goes wrong.

If the car is still not right when you get it back, immediately inform the shop, preferably in writing, and take it back as soon as possible.

Delaware Valley Consumers' Checkbook magazine and, a nonprofit consumer group, rates service companies and professionals. Inquirer readers can read Checkbook's full article offering advice on selecting and dealing with auto repair shops, and through Feb. 29, use Checkbook's ratings of area shops free of charge at