Considering purchasing a second-hand vehicle? Before you fork up the money, read these useful car buying tips to ensure you're receiving what you pay for.

A few reminders:

• When working on a car, all the time wear eye protection and be sure that your working environment has sufficient airing.
• If you're working underneath a car, locked it with a floor jack and jack stands or drive-on lift ramps.
• For all the time keep a strong supply of rags on hand in case you get greasy.

You'll need just a few simple provisions for the actions we go over today:

• Flashlight
• Penny
• One spotless white rag and a dirty one
• Carfax reports
• A pocket-version of Kelly Blue Book or a mobile device capable of checking used car value on-the-fly

Included in the instructional steps below are cost estimates for various fix jobs. If you are purchasing a second-hand automobile and meet any of these mechanical issues, you may be capable to use these prices as a bargaining point. On the other hand, these are just estimates. What your mechanic charges (including labor and actual repair work) might be different, and thus the listed estimates shouldn't be used as more than a wide-ranging information basis.

Checking Tire Tread. Using the penny, check the treads on each tire by sticking the Lincoln head side down and make sure that the treads cover the top of his head (you shouldn't see the crown of his head sticking out). Take two dimensions per tire, one towards the exterior of the tire and one towards the interior of the tire. If there are considerably different wear patterns on the same tire or within the same grouping (left front wheel, right front wheel, etc.), this is an alignment issue with the vehicle ($125).

If you see Abe's head popping through on any of these tires, you will need to restore that tire within the next 5,000 miles; this should be taken into account when factoring the cost of the vehicle ($60-$150 per tire).

Checking the Engine and Transmission. This is the area of the car where some really luxurious stuff can go erroneous. First, you should ask the seller when the last time the car had an oil change. If he says less than 1,000 miles, when checking the oil it should still have a translucent-gold color. The oil dipstick on the car is almost all the time labeled yellow. While oil does get dirty fast, you should not be too concerned if it's a bit dark, Cars that have black oil immediately after a fresh oil change, however, may be burning oil or have an internal leak.

Check the level of the oil to make sure that it is within the manufacturer's specs. When examining the oil itself, run your fingers though it to see if there are any gritty pieces or metallic flakes in the oil. If these are present, it could signal a very serious issue with the engine. At this point, you should get an automotive professional to review the car, if you still insist on purchasing it -- otherwise this is a clear sign of a lemon.

The same theory applies to the transmission fluid. Repeat the above process for that unit. If your car has an automatic transmission, the dipstick will be labeled red or orange and the fluid should be clear, bright red and smell like motor oil, but a bit sweeter. If it's a manual transmission, the oil will be clear, light gold and smell a bit muskier than regular oil. If find anything such as black residue, grit or metal in the transmission fluid, you could be looking at a car that'll need some major repairs soon. If you suspect any serious problems here, get a professional inspection first, before buying the car. Otherwise, you should walk away from the deal.

Checking the Axle and Steering Rack. In order to check the axle and steering rack, you'll need to jack the car up and secure it so you can get below the vehicle. Perform this check on one wheel at a time, if not you have a set of jack stands.

As most cars are front-wheel drive, raise each side and get the wheel off the ground. Inspect the rubber boots on both the axle and the steering rack to ensure none are ripped or torn. With your hand, grip each unit on the bar and wiggle it around. Rips or excessive play will require replacement immediately or in the near future (axle, $200; steering rack, $600-$1,200).

While the wheel is off of the ground, grab it by the tire and torque the tire back and forth to check for excessive play -- particularly from the bottom of the wheel. While the wheel may move back and forth under normal steering motions, it should not come in or out or up or down. If it does, you may have a bad ball joint ($200-$400). If you car is rear-wheel or four-wheel drive, you should check the axles in the rear as well.

Checking for Flood Damage and Lights. To check for flood damage, you'll want to dampen a clean white rag. Next, wipe the damp rag under both front seats to see if any rust comes off. If there is rust residue, the car is likely to have been flooded at some point. You should also pay attention to the carpets and the exterior of the car (wheel wells) to see if there are any noticeable flood lines, or if the carpeting is unusually new in appearance vs. the age of the vehicle. Another tell-tale sign of previous flooding would be multiple (more than two) electronic failures in the vehicle (windows, switches, etc). Any car with a flood history should be deemed as a salvage car and priced accordingly.

Lastly, check all of the lights on the exterior of the car to ensure they operate properly. Have a buddy sit in the vehicle and test all of the lights while you inspect from the outside. You should also get inside the car and check to make sure all of the major functionality is working (e.g. A/C is cold, wipers move, radio, etc.).

Test Driving a Used Car. Once you have a good idea of what's going on with the car, you must drive it at both low and high speeds to analyze its behaviors in different situations. During the low speed examination (less than 35mph), drive with the window down so you can listen for any mechanical clanging. You may want to find a large-empty parking lot so you can drive with the steering wheel in a full turn (360 degrees) both ways going forward and backwards. By doing this, you'll be able to hear any crunchy noises coming from the suspension or drivetrain. Be sure to also launch the car from a stand-still position at the same time as barely holding the steering wheel to see if the car pulls either left or right. This will signal whether or not the vehicle has proper arrangement.

When driving the car at high speed (more than 50 mph), check for any rumbling or looseness in the steering wheel or coming from the floorboards. This drive should be done with the windows closed, because the wind may overpower and mask any sounds you might hear. In conclusion, you should absolutely test the brakes on the car by finding an open road where you can make hard braking from 50 to 0 mph several times.

Checking the Carfax Report. If you're at the end where you want to pay for the car, you should get a Carfax or similar history of the car. While never fully fool-proof, these reports will let you know if any major accidents or thefts have occurred. It should also provide a basic maintenance schedule (if the owner was maintaining the vehicle using a dealer mechanic).

Should you find any red flags, you may be able to use this to your advantage and have more bargaining power; or it may be reason enough not to acquire the car at all. If you have severe concerns, but are still contemplating purchasing, take it to your regular service supplier and have them look it over ($150-200).