Apparently you would ignore the expert, keep driving, and pay a hell of a lot more when it actually seized up on you.
You are assuming a lot things:
1) That I expect to be driving the car in 10 years;
2) That the cost of buying a new car after 10 years or so would be more expensive to me than paying 5K now.
It is a basic principal of investment that money paid out in the future is worth less than money paid out now. It is partially because money you have today can be invested so you will have more money in the future. In addition, incomes can rise over time so a 5K bill to a college student is an extraordinary burden but the 20K cost of a new car is affordable to someone with a stable job.
The analogy holds for adaption. It the Canadian economy continues to grow at about 2% per year it will double in size by 2050 so Canadians living in 2050 may find the cost of adapting to climate change effects less than the cost of trying to stop emissions today even if the dollar value is more. When you add the inevitable technological and social change and the huge uncertainty wrt the effects of warming it becomes very hard to justify making significant sacrifices today in the name reducing CO2 emissions.