It used to be that "snap, crackle, and pop" were the sounds of breakfast. Today such noises are most familiar in parking lots and on highways across the country where vehicles of various sizes crash and crunch with enormous regularity.

Along with crashing and crunching is the social ethic of having an attractive, dent-free auto. It is a heresy, of sorts, to own a car that doesn't look as though it was just delivered from Detroit. Having a happy car, we are told, means a vehicle without blemishes.

While more and more of us are doing our own tune-ups, few have yet discovered the joy of body work. I was part of this unsullied majority until one day Vernon, my modest Volkswagen, was clobbered by a bus and suffered lacerations, shock, a stubbed wheel, a fractured fetlock, nerve damage, and much crinkling.

Check in hand from the bus company, I explored the possibilities for Vernon's rehabilitation. A dealer would always be available to do the work -- at rates that would humble OPEC -- so I decided to try it myself.

The initial task is to figure out what needs to be fixed. This may seem obvious as you notice the artistic manner in which the rear bumper has been spot-welded to the glove compartment. However, consider this idea. If the bumper has been demolished, what about the brackets or whatever holds it to the car? Can they be straightened or are new fixtures needed? Check the appraisal report used by the insurance company for specific information.

The thought of repairing a car assumes that parts are available. The first source to consult are local dealerships. If you drive a Farcel Vega, Zaporozheto, Chrysler or other obscure make the probability is that specific pieces are readily at hand only from dealers or specialized repair shops. If you are not in a hurry, or have more general needs, you should consider national mail-order catalogues, such as that offered by J.C. Whitney (1917-19 Archer Ave., P.O. Box 8410, Chicago, Ill. 60680) where prices are remarkably low. Also try local discount auto-supply houses which offer many items at reduced cost.

In many cases, however, it is worth checking the Yellow Pages under "Automobile Parts and Supplies -- Used and Rebuilt" or "Automobile Wrecking." Here you will find a collection of entrepreneurs who offer genuine parts built to the original specifications of the manufacturers. In fact, the parts generally were built by the manufacturers.

Used-parts dealers can be divided into two groups, those who are organized and "others." Organized firms have removed vital parts, stored them, and established retail facilities in some cases. Their prices are substantially below those charged by dealers, though it should be understood that parts may not be in pristine condition.

"Others" dealers are less organized. Their stock of goods is forever changing, largely because it is attached to vehicles which are being compacted for a final journey to the smelters. To the untrained observer, such supply operations look remarkably like junk yards.

To get the best deal call around and ask for the specific parts you need, their prices, and -- when possible -- what colors are on hand. Ask if checks are acceptable. If the part you need is not available, ask the dealer to suggest another firm which might have the required item.

Working with junk yards is a little different. You need the same phone calls to establish what supplies are available. Prices very according to the market, your skills as a negotiator, and who removes the needed part from the deceased vehicle's carcass.

In my case I needed the rear end of a VW. I found a junk yard with a car that had committed autocide by ramming into something large and immovable. A deal was struck and for $50 it was agreed I could remove whatever goodies I wanted.

If there is a hell for evironmentalists, a hint of things to come can be found at many a local junk yard. The very ground oozes with nuts and bolts. in this mire there are bargains to be had, but certain rules must be followed.

First, do not wear anything with ruffles. It pays to be attired in the oldest of old clothes, boots (preferably steel-toed), and work gloves.

Second, if you spot a large dog with more teeth than a zipper and a terminal case of mange, do not disembark from your car. This is the proverbial junk-yard dog and it is equally at home chewing on a ratchet wrench or human leg. Ask that it be contained, preferably down wind.

Third, you must bring your own tools. Good items to have include a cheap set of socket wrenches, pliers, several types of screwdrivers, and a large hammer for fine work. An idea of the tools you will require can be gained by examining the damaged areas of your car.

Work conditions down at the junk yard are, well unique. My scrap VW was conveniently located on top of a Plymouth. By standing on the Plymouth it was easy to unbolt the VW's fenders, particularly since the wheels and tires had already been removed. While I was there I also liberated needed car mats and various pieces of scrap that may have future value.

The major advantage of removing body parts, aside from lower cost, is that you have an opportunity to practice basic mechanical skills on someone else's car. This is an occasion not to be missed, especially if you have a limited automotive aptitude.

Once the parts from the junk VW were salvaged, it was a fairly simple matter to attach them to my car. Rather than paint each piece after it was in place. I elected to paint each part separately before attachment. This made it practical to work indoors with smaller items.

It should be said that the time and labor involved was not overwhelming. The work produced both a certain satisfaction and a sense of resignation from the idea that my efforts were merely temporary.Sure enough, within a year Vernon again was suffering from assorted scrapes and bruises. In fact, right at this moment, I'm looking for a right door to a '72 VW Super Beetle, sort of a reddish-orange, and there's this junkyard . . .