It's because you're trying.

Serious comment (not for you specifically but other people that might be able to use this advice.):

Stop trying and just be yourself. I know, cliche, but if you really want women/men/people in general to like you for you, then YOU have to like you for you.

What do you absolutely LOVE to do? Judging from your name, modding cars? Do you love cars? Great, me too. If other people don't, who gives a shit, this isn't about them so don't look for their approval. Stop trying to do things that other people love and do what you love. Talk about cars, learn everything you can about them and be enthusiastic as hell about them. This goes for anything that you absolutely love. It could be music, photography, sports, wine, or anything else that you love to spend all of your free time doing. Be passionate about your hobby and you'll eventually become very good at it. Use that to build your confidence. At that point you won't have to try anymore. People will come up to you and talk to you, because they see how happy, nerdy and passionate you are when you talk about your hobbies, and they'll want you to share some of that happiness with them.

Spending time on your own hobby also helps you deal with the fear of rejection. When you become good at something, you can't help attracting some bad attention. You'll get negative opinions about your hobbies from some people no matter how hard you try or how good you are. That's just human nature. But learning to deal with that rejection by not letting it affect your morale will help you stop seeking approval from everyone. Once you learn how to deal with rejection, it will make it much easier for you to meet anyone, anywhere by just being yourself and not trying.

I know a lot of people in that situation that are wondering why it's so hard for them to meet new people, especially in their late teens and some even older than that. It doesn't have to be that way and step one is to improve yourself. I hope this helps someone out.