Yes there is, but that does not change the fact that you have a monopoly over Ford Mustangs, not all cars.  It matters not if you use a spring, and I use a tensed rod.  My mousetrap is not your mousetrap.  ANd we both can sell them.

You have a monopoly over all (traditional) cars if you can patent the design for a car with broad enough parameters (e.g. motorised vehicle with wheels). Yes you could still try and make a sail powered car, or a plane, but it doesn't affect the fact that that person has a monopoly on cars.

You can have as narrow or as broad a patent example as you want, but whatever happens, the person with the patent has a monopoly over what's been patented. Other people can't compete by using the idea but not copying the product it's used in directly (although the specifics will depend on the terms of the patent). The alternatives are also likely to be more expensive, and in some cases significantly more expensive, which can then allow you to have an effective monopoly of an entire market until such time that the alternatives become more cost efficient.

This is why they have patent clerks.  You can't necessarily get a patent just because you apply for one.  The patent office would not allow you to get control of an entire industry.

From dictionary.com:

pat-ent: [pat-nt or, for 10, 12–15, peyt-; especially Brit. peyt-nt] - noun

So you can patent a specific invention (albeit that invention could be fairly generic the patent office would not allow you to patent an entire industry, ie even prior to the day of the automobile you couldn't patent the entire automobile, but you could patent the parts that went into making an automobile.)

Mo-nop-o-ly: [muh-nop-uh-lee] -noun, plural -lies

And this is the key, being able to control exclusively a commodity or service in a particular market (ie making all mouse traps not just making a specific mouse trap) or control that allows you to manipulate prices.

There is a difference between the two.