Hi Derrick,
I'll take a crack at a critique.
Constructive, of course.
Logo: Seriously consider having a professionally designed logo. Don't let a friend or family member do it even if "they can do that kind of stuff". A good logo should work in color or b&w and at varying sizes.
Header graphic: My ignorance rears its head here as I can't tell what kind of car that is. The back end reminds me of an AMC Gremlin, but I'm guessing it looks like that because of the way it was cut out of the source image
As others have said, putting a more familiar car in will let people make a more personal connection. If you're going to stick with grays as your theme, then definitely try to get a vehicle in a color other than black, white, silver or gray. You could then use a color from the car as an accent color somewhere in the rest of the design. What's in the background here?
Layout: I don't know what tool you're using, but from one of your responses it sounds like you may not have the flexibility to tighten up the layout so everything lines up correctly, but that's typically a hallmark of a professional design. It may also be that it looks good in IE and not so great in Firefox (which I'm using). It can be tricky to get a site to play nice with both browsers, but you should target those two as they have the largest user base.
If you don't need the breakout box on the right on every page, consider removing it. BTW, the bottom of this box is missing the black outline in Firefox.
Fonts and text layout: You're always safe with standard fonts. Unless you have a good reason to use a different font (not just for the sake of being different) then you can try out other possibilities. Just keep in mind that readability is your goal. Is there a way for you to get more clear space around the text blocks. All the text is way too close to the edges and makes it look very crammed.
Copy: Make sure your copy is well written and easy to read. I noticed that on your home page you don't ever mention the word "detail", yet that is what most people who are looking for you are going to enter into their search engine of choice. I can hardly stop myself from rewriting it for you, but I gotta get to bed.
I'll take a crack at a critique.

Logo: Seriously consider having a professionally designed logo. Don't let a friend or family member do it even if "they can do that kind of stuff". A good logo should work in color or b&w and at varying sizes.
Header graphic: My ignorance rears its head here as I can't tell what kind of car that is. The back end reminds me of an AMC Gremlin, but I'm guessing it looks like that because of the way it was cut out of the source image

Layout: I don't know what tool you're using, but from one of your responses it sounds like you may not have the flexibility to tighten up the layout so everything lines up correctly, but that's typically a hallmark of a professional design. It may also be that it looks good in IE and not so great in Firefox (which I'm using). It can be tricky to get a site to play nice with both browsers, but you should target those two as they have the largest user base.
If you don't need the breakout box on the right on every page, consider removing it. BTW, the bottom of this box is missing the black outline in Firefox.
Fonts and text layout: You're always safe with standard fonts. Unless you have a good reason to use a different font (not just for the sake of being different) then you can try out other possibilities. Just keep in mind that readability is your goal. Is there a way for you to get more clear space around the text blocks. All the text is way too close to the edges and makes it look very crammed.
Copy: Make sure your copy is well written and easy to read. I noticed that on your home page you don't ever mention the word "detail", yet that is what most people who are looking for you are going to enter into their search engine of choice. I can hardly stop myself from rewriting it for you, but I gotta get to bed.