You can promote your site in free classified sites, forums, online groups etc.. You can also create a blog and write some articles related to your site's services or products.. Other methods are article submission, directory submission, joining in social bookmarking and networking sites.
Everything is provided in this forum but if you don't have tome or don't know how to use the search feature, download the free seo book here.
Having a look at your site all I can see is product links (all to Amazon). I think your visitors would get more value from you including content and other relevant info on your site. Write up some reviews of the goods you are selling, provide specification details about different Audi's and perhaps latest news about Audi's or other German cars.
Hmm... consider new domain name (for example: yourcarparts dot something...) and read these traffic getting tips - could get you some ideas