Hand with wrench. Auto mechanic in car repair .Here are the next two terrible things you could hear from your mechanic of GMC Trucks in Ontario, Canada.

He says, “You just added transmission fluid to your brake fluid reservoir.”

Now, if you manage to catch this mistake before you actually get back into the car and step in the brake pedal you might get by with a tow and a new master cylinder. Even this is going to cost you around $800.  But the alternative means that the petroleum based product gets pushed through the brake system and everything must be replaced. The oil attacks the rubber seals and everything with the exception of the metal brake lines. Once you use those brakes, you are looking at a $2,000 fix.

He says, “Do you see on the battery where it has a positive sign and a negative sign? It wouldn’t have actually mattered if you had matched red and red or black and black, but because you did red to black… well, your computer is totally fried.”

Lets keep this real, there is a possibility you are looking at $100,00 plastic surgery. You see, in a lot of cars, there is a productive circuitry that protects you if you accidentally reverse the polarity of the battery when you hook up jumper cables. This is not true of all cars though. If you have one of the unlucky cars, you may be looking at having to buy an all new computer for your car and possible a few new wiring harnesses as well. In this case, you are looking at about $1,500. As if worse was possible, you might gain so many confounding electrical problems that the best thing you could hope for is your engine to catch flames. Even if your car escapes unscaathed, blowing up one of the batteries will result in that plastic surgery we mentioned.