There is a saying "Men and their Cars.' Well if you are on those women who have partners who love and adore cars then you must not take that away from them and even if it is annoying because your partner waste more money and spend more time with their cars. Instead of getting jealous and getting irate over your partner try supporting him once in a while and you will see a smile on your partner. Isn't that we always wanted to make our partners happy? Although it takes some time and research before you could relate to all what he his talking about but knowing what your partner likes could make more meaningful communications that could lead to a more fruitful relationships.
Here is an example. You could say to him like this "You know I found this exhaust tips and read about it. It said that having a great mufflers and exhaust system could be beneficial to your car especially when we are speaking of gas mileage. Aside from the aggressive and powerful tone that it gives when you push that gas pedal, it gives more additional hurl on your horsepower. I think you should upgrade your exhaust system. what do you think?"
From that statement of yours, you will surely get his attention to start a long conversation and not only that, you will be able to spend quality time with him even when he doing something on his car. It may be difficult at first but in time you will get the hang of talking about cars. You might be surprise that he too will make initiatives in taking you and accompany you for a shopping spree.