The answer is almost always no. Gap insurance covers the gap between the value of your car and the money you owe. When you drive the car off the lot, there are many times in which you will be “underwater” meaning you owe more than the car is worth. This gap can be filled with gap insurance. This is basically the dealer saying, “If you total your car to the point in which it is no longer driveable you will need this insurance.”
When you get a new or used vehicle and you are driving it off the lot you are extra cautious. Car dealerships know this so they will do their best to sell you all kinds of extra packages. If you truly want something comparable to gap insurance contact your car insurance company first. You can also shop around and find a much lower rate. On a used 2012 BMW 535i the local dealership quoted me at $897 for gap insurance. This is ridiculous.
If you want to fill that gap take the extra $897 and pay two extra payments on your car. I would strongly suggest never buying gap insurance from a car dealership; especially at the price they offer. Remember that gap insurance is negotiable so you can tell them you have been quoted at a much lower price and they may match it.
Note that the car dealership will usually try to sell you a warranty along with gap insurance. If you don’t watch out the dealership could tack on another $5000 to $7000 if you are buying a BMW that is over $30,000. Read over every line on the contract before signing it. My payments went from $625 to $465 by taking off all these extras including Gap Insurance, a specialized maintenance package and a long term warranty.
If you think your car is going to break down in the next 30,000 miles I strongly suggest you consider buying a different vehicle. BMW’s were built to last not to break down before 100,000 miles. Set aside all that extra money and when a problem occurs use it then. I would be willing to bet you will never use most of this money you set aside. Go out and buy some brand new golf clubs or a driver and enjoy yourself.