Automobile niche is a good field, to create a website or blog. Have a lot of content and articles in this field.
I think this is the most risky niche. when you will talk about medical issues, sensetive issues like sex, pill, drugs etc will come forward. which is very risky for adsense!
Go with something you like first, like things you are passionate about since they help make life easier for you From there, look for keywords you feel you could profit on then focus on those
From personal experience, I can assure you it's difficult to continuously create content for a blog in which you are not very interested in. Are you really interested in car loans, or hair loss, or medical education? Just because a niche may typically have a high click-through rate, the last thing you want your site to become is a daily chore in which you have little interest or motivation to work on. This frustration will inevitably show in your work. If you have an interest in something specific, and you would enjoy writing about it on a regular basis, that's the best choice in terms of your adsense website. Unless, of course, you're really passionate about pornography or something similarly against Adsense terms of service.
Loving this post by matt_62. The best advice I would give to anyone starting out with adsense is to write about something with a passion. What's the best blog post you've ever read? A tech one? Or something that talked about the best way to catch bass fish you've ever heard about? Fishing with a passion! Build that aspect in to your text and you won't go wrong. Passion beats factual everytime! Not to say you mustn't know your facts! Quote/share/facebook etc. That the best thing about this whole game!