Hi there. Nice job on your site so far! I'm new to the forums, but I work on very large websites for a living, so hopefully this will be helpful to you.
First, your phone number is small and blends in with the background. Don't hide it!
I agree that the before and afters are great and should be front and center on the first page. Instead of answering the question "Why do you need a detail?" with all that text, show them a few of your photos and they'll be sold in no time. You can always keep the text lower on the page if you want.
If you decide to keep the before/afters in a slideshow, speed up the transition to reduce the chance that someone glancing at the site will only see "before" but think it's an "After." You could probably do without the slideshow and it would have even more impact.
If your market is really price-conscious, you might consider adding a price teaser on the front page. Think: "Interior cleanings starting at $39." Put it in a simple "starburst" graphic (like a sale tag) to attract attention, and set it to link to your menu page.
Also, if you're marketing to a family-oriented crowd, the photo of you smiling and looking professional is a great touch. You might want to consider removing the filter and cropping it a bit tighter so that it's easier to see your face...don't want to look like you're hiding.
Finally, the menu page. I enjoyed the picture of the tattoo "artist", but the meme might not be appropriate for your clientele. That spot be a great place for another before and after shot. Also, I agree that the number of clicks to get to the menu is too much. Better to have a single menu with a range of prices for vehicle sizes, OR just put a note at the bottom: "Larger vehicles extra" or "Trucks, SUVs, and Vans: add $20 to package price." You can play with the wording based on your knowledge of your local market, but those are some ideas to get you started.
In terms of the actual pricing, do you really need four tiers of vehicle sizes, or could you simplify that somehow?
Congrats on getting this far in the process. Building a great site can take a L-O-N-G time. Keep up the good work.