You're definitely heading in the right direction, MocMan, and way to be persistent. Don't get discouraged by a few negative comments. I go through 25+ variations of a logo before I find the perfect one, so you just need to be patient and avoid settling on a logo you're not happy with. It really is a reflection of your business, and the more professional it looks, the more professional you're going to appear to your customers. Keep at it, even if it takes a few weeks--it will be worth the wait.
As for your logo, here are my comments / suggestions:
First of all, great job on ditching all of the layer styles and colors. Save those for after you get a solid, black and white logo going. Once you do, I think the effects could really add something if you go with a glossy feel. Glossy is usually overrated and sometimes seen as unprofessional, but given that your product revolves around making cars shine, I believe it would be appropriate. For example, Logitech is one company that has a solid black and white logo that they can print on mouses and speakers where color cannot be used, and then they have a fancy, colored logo that they use for everything else:
I really think your font choice is what's hurting the logo the most. Slim, hand-written fonts are some of the hardest fonts in the world to work with, especially in logos. Yes--you can make them work--but it's going to be a challenge. Have you experimented with Helvetica, yet, as others have mentioned? It's a great font and the possibilities with the various font styles are endless. If you're not a fan of that font, try other fonts that have numerous font styles (light, regular, medium, bold, black, etc) Experiment with making MC Car Care bold, and Products in a light font underneath. Experiment with your kerning (the gap between the letters) and making MC Car Care tight, and products really spaced.
Another aspect that I feel is missing from your logo is a sense of... "togetherness", for lack of a better word. I feel like you have a word here, a word there, and nothing to bring it all together. Take a look at how these logos are tied together:
Also notice how both of these logos would look great in black and white, but yet they look great fancied up. (Note: I imagine both of these companies are your competition, so you don't want to make anything that makes a customer think, "Hey, that reminds me of Meguiar's logo!"). Sometimes it's good to take a look at other logos to get ideas, and to see what works and what doesn't. When you have time, stop by a book store and take a look at a book like "Logo Lounge", which is filled with nothing but thousands of logos. It may help spark an idea for you.
One more thing: MC Car Care Products is plenty long enough for a logo. Ditch the phone number and the slogan--it's just too much text for one logo, and it's going to be impossible to read when scaled down. There are other places to include your slogan and contact information other than in your logo.
I would throw something together for you as an example, but I really think you're getting closer with each version, and you know your company far better than I do. If you get discouraged to the point of settling, shoot me a PM and I'd be happy to help you out some more.
Keep it up, Mocman--you're definitely getting there. Now, any tips for me for cleaning off hundreds of tiny sap spots from the hood of my car that fall from the tree in my yard?
