One trick in buying auto parts is to learn to recognize the difference in price and cost. Price is the amount initially paid. Cost will include, damage caused by inferior parts, repeat replacement cost and other things damaged by part failure. A $49.00 part, which works six months, has a higher cost than a $150.00 part that last ten years. This is especially true when the failure causes damage to other components. A cheap air conditioner compressor can fail and contaminate the entire system.

Recognizing part quality is VERY difficult, even for professionals. Many parts on the market today are substandard. Several do not even meet their manufacturer’s specifications when new. Many name-brand manufacturers sell first, and second line parts and counterfeit parts are showing up more frequently.

  A lifetime warranty; The lifetime warranty has become synonymous with junk. Parts so cheaply built that giving multiple replacements does not change the profit. The plan may be; the buyer will get tired and go away eventually. A lifetime warranty usually means a very low quality part.

 New; Ironically many parts that were traditionally offered as rebuilt are now available at a lower cost "brand new." These parts are often cheap knock-offs and usually inferior quality. C.V. axles, starters and alternators are some things to watch. A quality rebuilt part is an original part, restored to good condition. Cheap new parts often do not even remotely meet the quality standard of the original.

 Brand names; Several companies that offered quality products in the past have been bought and sold multiple times. The name remains, but no semblance of the original quality.

 Second lines; Brand name part producers often sell cheaper lines of questionable quality. Delco, for instance, makes some original equipment parts for General Motors. They also sell a cheap, imported line, packaged in the same type box. Without knowing the part number, it is difficult to learn which you are getting.

 Aftermarket dealer parts; Dealerships also sell second-line parts in many cases. For instance, Ford has original equipment brake pads and Motorcraft pads, which is simply an aftermarket pad. Unless you specifically ask, you may NOT get a genuine part from the dealership.

Normally, buying parts from the vehicle manufacturer will offer the best chance of getting a quality part. This is particularly true with Toyota and Honda, which offer very high-quality replacement parts. General Motors, Ford and Chrysler all have second lines, and more care must be taken. Other import lines vary, so be certain to ask if the part is original equipment, also known as O.E.M.

This can be confusing, but in the US and Canada, left is the driver’s side and right is always the passenger side. A professional mechanic will order parts by left and right, but there is nothing wrong with using the side. If there is any doubt, ask for driver or passenger sides; it may prevent a return trip.

The vehicle identification number or VIN is the seventeen digit number, on the tag at the base of the windshield. When buying parts from the dealership, this number will all but guarantee the right part. Some parts-people may be reluctant to use this number, thinking they know the part. Always give only the VIN number and see if the part person says the type of vehicle. If they do not, they may not be using the number as they should.

There will normally be an option's decal on the vehicle and this sometimes provide information not even in the VIN. On Chrysler's products, the decal will usually be on the driver’s door.

Vehicles from Ford, often place the decal on the driver’s door pillar. This tag will provide gross vehicle weight, wheel base and much other very useful information. Taking a digital photo of this tag and bringing it into the part store can save a great deal of wrong parts.

On General Motors, the option-tag list codes that correspond to the type and level of accessories on the vehicle. The tag is often in the glove box but may be on the trunk lid or even on the spare tire cover on some models. A digital photograph can really be a help, making this information available.

A picture is worth a thousand words and with cell phones and digital cameras, very easy to create. Taking a picture of the hard to describe parts is a good way to show the part person what you need. Writing any numbers from the part on a note will also help. If possible, removing the part you need is best and bring it with you. It is amazing how many parts look very similar, but will not work. Comparing the part before leaving the counter can save much grief.

A good parts-person is a valuable ally and can save you a lot of money. Start a pleasant relationship by asking their name and noting it on your parts’ receipt. If there is a problem, you will know who to ask for. If there is no problem, you will want to ask for this person the next time you need parts.

The parts-salesperson is normally paid based on what they sell. Doing as much business as possible with a single person, will build a relationship much quicker. The most experienced parts-salespeople are a wealth of information. An occasional box of donuts, can be worth many times the cost and is a nice gesture for good service.

 Provide the VIN number rather than the year, make and model.

 Ask if the part is an original equipment manufacturer (OEM) or not.

 Think lowest overall cost, not price

 Use pictures to show what you need.

 Bring the old part with you, if possible

 Ask the parts-person if this is the highest quality part available.

 Use the same part salesperson when possible

 Reward good service