These driving idioms are frequently used in informal English. Learning them will help your English sound more natural too. Let's first review what an idiom is: Idioms are fixed phrases—that means you can't change or substitute other words—and the meaning is metaphorical rather than literal.
Here are a few more examples to help make the meaning of these driving idioms even clearer:
in the driver's seat: in control or in charge of a situation
— You always want to be in the driver's seat in this marriage and what you don't understand is that we should be more like copilots in a partnership.
— Who's overseeing this project? Everyone can't be in the driver's seat at the same time.
drive yourself into the ground: to work so hard that you become sick or exhausted.
— If you keep working so much overtime you're going to drive yourself into the ground.
— I'm really worried about my father. The last time he drove himself into the ground he had a heart attack.
— You're sick so often because you continue to drive yourself into the ground with all this volunteer work. You really need to get more sleep.
shift gears: to quickly or suddenly change what you're doing or thinking (often when handling a challenge a problem)
— This afternoon we'll switch gears and break into small groups to discuss how to implement these proposals.
— The beginning of the book is a bit boring but the story shift gears in the third chapter and gets really interesting when the main character loses her job and travels to Africa.
drive (someone) crazy: to greatly annoy or irritate someone.
— These commercials are driving me crazy. I wish I could watch the game without interruptions every two minutes.
— What are our neighbors doing upstairs? The noise is driving me crazy.
asleep at the wheel: not doing or paying attention to problems or something that's important.
— We're out of photocopier toner and paper and I need to print a report. Whoever's ordering office supplies is asleep at the wheel again.
— I fired my secretary because she fell asleep at the wheel and forgot to purchase my ticket to Friday's conference so I had to buy one at the last minute for $3,500.
drive to distraction: to confuse or distract someone so they can't focus; to greatly annoy or frustrate someone.
— This construction is driving me to distraction. I'm going to work at the café for a while.
— There's a beautiful girl in our chemistry class and she's driving everyone to distraction.
— I hate it when people wear perfume to the theater—it honestly drives me to distraction.
drive at something: what someone is really trying to say or suggest
— Did you notice what her mother was driving at when she asked where your father graduated from school?
— I have no idea what the district manager was driving at this morning at the sales meeting. Do you?
— What we're driving at is that we prefer a more classic and traditional style.
middle of the road: not controversial, moderate, liked by most people
— My youngest daughter never does anything middle of the road so I'm not surprised you were shocked when you met her.
— I really need to get back to New York City where there's some excitement; living in the suburbs is so middle of the road.
third wheel: someone who tags along with a couple
— Is there any way we can go out alone tonight?
— I'm tired of your little brother always being the third wheel.
— I really hate being the third wheel but it's better than staying alone at home every weekend.
my way or the highway: used to say someone else has to agree with you (or leave) because there's no other choice
— I'm sorry that you don't like doing chores but until you turn 18 and move out of the house it's my way or the highway.
— I told my wife that I'm willing to compromise on a lot of things but for our next vacation it's going to be my way or the highway.