Sure, all those high-tech gadgets and systems on your new car are cool. But have you ever stopped to figure out what they’ll cost you if and when they go kaput?

Lock your seat belts!

Let’s say your luxury sedan has been in a fender bender. You sharply smacked the car in front of you when the light suddenly changed to red.

The bumper is now a twisted plastic noodle, the front of the hood looks like an accordion and a couple of air bags in the dash and steering wheel deployed.

It will be a pain in your daily schedule to get the car fixed, but no one was hurt, so how bad can it be?

You roughly estimate $3, 000 to $5, 000.

Then you get the repair estimate: $15, 000 and your heart skips a beat at the thought of increased insurance premiums or the possibility your car could be written off as totaled.

As cars have incorporated more high-tech safety and convenience features — some optional, some standard equipment — the cost of repairing them in the case of even minor accidents or just plain malfunction has risen dramatically.

“There are some really great features being incorporated into more and more cars, but the cost of repairing or replacing these systems is a lot more than many owners realize, ” says Russ Rader, spokesman for the Insurance Institute for Highway Safety, which tracks such trends.

New car features, big repair bills
What worries some consumer advocates is the likelihood that most car buyers these days are unaware of the potentially huge repair costs associated with the tide of new features that have been incorporated in cars and trucks over the last five years.

A hypothetical front-end collision in a 2006 Mercedes-Benz sedan could — in addition to the body damage — destroy the adaptive cruise control, which uses radar units mounted in the front bumper to keep track of traffic around the car. The cost to repair: $3, 342. If your optional Xenon headlights and their washer system are also damaged, add on $1, 644 per light — or almost $6, 700 over and above the cost of the body damage.

If you own a sport utility vehicle like the Cadillac Escalade, take care of those big, heated, outside rearview mirrors. Knock one off in a parking garage and it will cost $604 to replace.

One of the coolest gadgets that came out recently is the rain-sensor windshield wiper system that actually turns on your wipers when needed. But, if a falling tree branch shatters your windshield and also knocks out this system, expect to shell out $500 beyond the cost of the glass to get the rain-sensor system replaced.

Another big-ticket item: those backup cameras that are starting to appear on everything from luxury sedans to SUVs to minivans. They’re great safety items that eliminate dangerous blind spots, but if a parking lot smack down demolishes the one on your Lexus RX330, it will cost $4, 336 to replace.

What’s more, it can be very difficult for car shoppers who try to consider the cost of repair for all those conveniences and options to get a firm handle on the potential financial risk. Consider the hot new feature on the 2007 Lexus LS 460 sedan, automatic parallel parking, which calculates the size of an open parking space and, using sensors in the bumpers, actually parallel parks your car — hands off the wheel, but foot on the brake.

Just figuring out exactly how much the option costs is difficult. Lexus doesn’t sell it as a stand-alone option, but packages the system with other features ranging in price from $1, 200 to $4, 800.

So, calculating what it would cost to repair the automatic parking function, if it were damaged in a crash or failed entirely after warranty, is near impossible. But collision repair experts say that a general rule of thumb is that the cost of repairing or replacing an option can run five to seven times the cost of the option when the vehicle was new.

Satellite navigation: Once only available on vehicles costing $50, 000 or more, even garden-variety, 2007 Hondas can now be ordered with an in-dash navigation system. The cost of the sat-nav option is still between $1, 200 and $2, 000 on a new car, but should the unthinkable happen and your 5-year-old hurls something at the navigation screen and smashes it, it could cost as much as $7, 000 to replace, especially if the screen also incorporates control of other functions, such as the audio system or climate control.

“One of the issues that most people aren’t aware of is that manufacturers have piggybacked systems onto other systems, so that when one is damaged, it will take out other functions, ” says Kim Hazelbaker, senior vice president of the Highway Loss Data Institute. Whereas years ago a faulty power window usually involved just a switch in the door, now the malfunction may be linked to a failure of a computer module that controls other things, as well.

Keyless ignition systems: Key fobs that transmit a low-power signal to the car, allowing it to be started by pressing a button on the dash — are all the rage. Just don’t lose the key fob. That could require reprogramming or replacing of one of the car’s control modules at a cost of $200 to $600.

Aluminum body parts: Another potentially costly area involves greater use of aluminum in vehicles. Some cars, such as the Audi A8 and the Jaguar XJ sedans, use aluminum almost exclusively in the body and chassis to cut down on weight and improve fuel economy.

The problem is that an aluminum car requires special knowledge and tools to repair — something that most body shops are not equipped to tackle.

Hazelbaker related a case of a man in Hawaii who bought one of the first Audi A8 sedans and then was involved in an accident. There was no place on the islands equipped to fix the car and it had to be shipped to California for repair at tremendous cost to the insurance company and depriving the owner of his car for months.

“Aluminum is a great material. Insurance companies don’t have safety concerns, but there are repair...