You can thank "high technology" for the death of the backyard mechanic.

Back in the 1950s, any kid with ambition, a modicum of talent and a set of socket wrenches could do impressive things under the hood of a car.You didn't need thousands of dollars in diagnostic equipment and a degree in computer science to work on a '51 Ford. The only "black box" on that car was the voltage regulator, and when it acted up, the standard repair procedure was to give it a good whack with the handle of a screwdriver.

You never rapped it with a hammer or wrench, it had to be the handle of a screwdriver. I don't know why. In the '50s, we accepted on faith what our fathers told us. If you were ever foolish enough to ask why, he'd give you The Look, and The Look was to be avoided at all costs.

Those who advanced beyond regulator rapping almost always began thinking about ways to make their car go faster. There were many ways to "soup up" a car, but one of the more sure-fire was to take an engine intended to propel a car weighing more than two tons and install it under the hood of a car weighing considerably less than that.

An acquaintance of mine did just that. He took the engine out of a wrecked Cadillac and placed it in his 1950 Ford. The result was a "Fordillac," and it was one of the better performers in State Street drag races, all the more so because it appeared to be a normal Ford coupe. I don't think we had learned the word "stealthy" back then, but that's what the Fordillac was.

Which brings us to this week's ride: a 1999 Subaru Impreza 2.5 RS.

Subaru has become a master at taking its existing products and by virtue of a tweak here and an add-on there, turning them into something else. The metamorphosis of the prosaic Subaru Legacy into the hot-selling Subaru Outback will be studied in marketing classes for years to come.

The Impreza, Subaru's entry-level car, has already been subjected to the Outback treatment, but for the '99 model year it has been morphed once again, into a hot little rally car called the 2.5 RS.

Subaru has taken the 2.5 liter four-cylinder "boxer" engine (meaning the cylinders are horizontally opposed) used in the larger, heavier Subaru Forester and Legacy Outback models and dropped it into the Impreza.

It's not the identical engine; the dual overhead cam of the big engine has been substituted for the SOHC of the standard 2.2 liter Impreza motor, but the horsepower remains the same at 165, and torque is actually boosted from 162 to 166 lb-ft (at 4,000 rpm) in the smaller car.

The result is an absolute gas to drive (to use a term coined by Frank Sinatra's Rat Pack back in the '60s). Like all Subarus, the RS has full-time all-wheel-drive, and its suspension package really hangs on through the corners. The five-speed manual shifter is a must on a car this sporty, and there are many cars costing more than twice the price of the RS

that aren't nearly as much fun in spirited driving. The old term "pocket rocket" fully applies to the RS.

But stealthy it is not. In addition to the big hood bulge, found on all Imprezas, it also has a huge wing mounted on the trunk lid; not a discreet spoiler, mind you, a foot-high wing reminiscent of those found on Indy cars and Formula racers.

Now, the Impreza RS is fast, but it's not THAT fast. During my week behind its leather-clad steering wheel, I would avoid looking at my fellow motorists as we waited for the light to change. I could almost hear them snickering at the old dude in the funny little car with the ersatz air scoop and the big grab-handle on the back.

I would find myself thinking about going to an auto body shop and getting estimates on removing the nose wart and the bustle hump and then I'd have to remind myself that I was only borrowing the car for a week and it wasn't really my problem.

In fairness, it could be just me. I never actually saw anyone pointing and giggling at me, and my teenage daughter proclaimed it "cool," so maybe it's just my innate conservatism at work here. I am certainly not even close to the market niche at which Subaru is aiming the 2.5 RS.

But if I were to win one by making a hole in one at some charity golf event, I would head straight to the body shop to get an estimate on losing the scoop and the wing. Then, even I would proclaim the RS to be, indeed, cool.

Fuel mileage is rated at 22 mph in city driving and 29 on the highway, pretty lame for a subcompact coupe, but Subaru's boxer engine has always been thirsty for its size, and the four-wheel-drive doesn't help, either.

Base price for the Impreza 2.5 RS is $19,195. Carpeted floor mats, a CD player and upscale speaker system for the stereo, and a keyless entry system, added $1,119. Delivery charges of $495 brought the bottom line to $20,809.

This is thousands more than you would pay for most small coupes, and you could buy any number of larger, more luxurious cars -- the Honda Accord comes to mind -- for the same money. Heck, the RS doesn't even have cruise control.

But the Impreza RS is a specialty car, a niche vehicle aimed at a small segment of buyers. And specialty cars, like specialty anything, are never cheap. Those who are determined to stand out from the crowd must pay for the privilege, and rightly so.