Hi Tim,
I'm in a similar boat to you with the unsurity of decent and ethical backlink profiles. From what I can gather from research and experience, the initial idea of backlinking has changed dramatically. Originally you could literally produce blogs, forum signatures, press releases, articles, social bookmarks and generally any type of link (spammy or not) and see some form of benefit in your rankings. However google have upped their game and since the Panda and more recent Penguin update, the backlink world has become ever so harder to understand.
To answer your question, most SEO'ers would suggest researching your high ranking competitors backlinks and basically high-jacking them (in a nice way). I would suggest doing the same:
1. brainstorm what you believe to be your prime keywords (car gadgets, satnavs, parking sensors etc.)
2. Use Googles keyword tool to see what the local and worldwide searches are like ( http://goo.gl/ah50 )
3. Pick the keywords with the most searches (and least competition if there are any) and search the keywords in google (best to use private browsing to ensure you get true results and not tailored to your search habits)
4. Use a backlink tool on the websites that appear on the 1st page for that keyword (sorry but I cant remember any of the tools off the top of my head, but their's quite a few out there, some are add-ons for Google Chrome or Firefox) to research where they are getting their backlinks from.
5. Approach the websites and inquire if you can also have a backlink from them (some will be directorys that you may be able to submit to for free or for a fee, whilst some may be unobtainable (newspaper articles etc.)
Also you may want to submit your website to the free DMOZ directory, but please note it can take a long time for the submittion to become active, if at all.
Hope that makes sense and helps. Please dont shoot me down if anyone disagrees, just adding my contribution/opinion 
Best of luck and nice website.
