1) get a few links. google will likely send you more traffic if they see others linking to you.
2) ask people to link to you on the site.
3) add some social buttons ("share this on facebook" and "+1 this"). Also, try to get it on pinterest. You might create a "5 car tips" image that could get shared as an image on pinterest, generating traffic and likely getting some blog links.
4) split test your adsense. use all three units, plus link units. then split test which ads work better when placed where. Think long term. 10% better RPM will add up. You probably want to add a skyscraper.
5) add links to amazon (through their affiliate program) where useful. need a tool for that? buy one here. I like to link to searches for products, rather than actual products. That way, the user sees all the available products rather than just the one you selected, and if that particular product goes away (which it might, because in a niche, you are probably linking to products sold through amazon by others - and they can change often - or be out of stock).
6) add content occasionally. google likes "fresh" content. changing things around, adding new articles, etc. will help you over the long term.
7) tailor your html titles to describe the content, and don't have "how a car works" in every page. It makes sense, but you really want to tell google what's there, and adding the site-wide keywords might dilute the message.