I don't mind helping, but my time is limited, so I list just a few. Also, I do not know what car niche you're interested in - car news, prices, NASCAR racing, Formula One, etc. etc.
In addition, you can get various kinds of content to display on your site. Syndicated articles that auto update, articles you have to cut and paste, news feeds (RSS or Javascript), etc. The following are a mixture of these.
Here goes:
=> General Automotive
*
http://www.just-auto.com/affiliates/
(news + articles)
*
http://www.effectivecontent.com/auto.html
*
http://ezinearticles.com/?cat=Automotive
=> Articles
*
http://racingarticles.com/
(Not just racing articles - good content here!)
=>Automotive Website Tools
*
http://www.edmunds.com/products/tmv/add.html
(Used Vehicle Appraiser, New Vehicle Pricing Calculator and Finance Rate Estimator)
*
http://www.pistonheads.com/widgets/
(Newsfeeds, Classified Ads, Real World Price Guides)
*
http://www.jeep-classifieds.com/info/live_feed.asp
(Jeep Classifieds)
=> Motor Sports
*
http://www.sportznutz.com/syndication/
*
http://www.sportsdatabases.com/sdblive/sports_content/sports_content.asp
*
http://www.wildhobbies.com/news/default.asp?cmd=view&articleid=417
=> News
*
http://www.news4sites.com/newsfeeds/index.php
*
http://www.newsisfree.com/
=> Auto Technicians Meetup
*
http://autotech.meetup.com/share/
=> Free Automotive Courses
*
http://www.free-ed.net/catalog/crsemain.asp?nC=2&nD=1&nO=0
=> Other
* Check out
http://www.xongoo.com
A quick way to add news articles to your site is via RSS feed or Javascript. For example, cut and paste the following script in a webpage and see what happens. Easy! To customize the script go to
http://anyrss.maquis.org
<script src='http://anyrss.maquis.org/js.php?q=automotive&s=r'></script>
This should get you started.
And as profezor said before, Google it. But remember that a "car" can also be a "motor", "motorcar" or "auto" in other countries. And include words like "automotive", "vehicle", "free content" "syndicated news", etc. in your searches.
Good luck!