I am with DLB on the secondary pages and navigation sound. You could set up the home page to have the sounds and the use of Silverlight(unless that is Flash. I didn't pay attention), and then just use a jpeg for the secondary page navigation and banner. I am not a big fan of sounds on websites as I mostly have my audio off.
You want to make pages simple and informative. Get your information to whoever is visiting in a quick and concise manner. If things take too long or there is too much clutter a person will click off the website faster.
Sully has the right idea, go to other websites and look to see what might be working for them. It doesn't have to be a detailing site, it could be a band, e-commerce, or some other site. Bookmark pages that you find cool.
Here is a tech website that might be helpful with website design and even marketing.
SitePoint : New Articles, Fresh Thinking for Web Developers and Designers They are a publishing company for website design and backend stuff. They also have forums that could be helpful.
Take care,
Don