Best new first car under $20,000?

I'm a 16 year old guy and my parents want me to get a new car (they have less problems/repairs). The only catch is that it must be under $20k and I have to pay 25-50% of the price. I really want a 2014 v6 mustang, but my dad thinks fords are trash. Don't say anything about insurance, I know it will be high for a 16 year old boy on any new car.

How much power would I net?

I'm new to Ford Mustangs. I'm wondering how much power I could gain from a Trick Flow 380/375 top end kit and a Vortech v2 supercharger, I'm looking for over 400hp at the crank while still being CARB legal

Added (1). For a 1996-97 Mustang 4.6 GT

2000 ford mustang gt quarter panel?

I'm trying to find a 2000 ford mustang gt quarter panel. All I can find is stock from ford and its 1300 dollars. My number got a scratch and I have a huge dent on my quarter panel. My insurance said its scrap but its not a lot of damage. I'm looking for one I can buy off line that I can just weld on and paint.
I love this car. I waited 5 years to drive it and I had a month with it.

2001 Ford Mustang Convertible top motor?

I have a 2001 Ford Mustang Convertible, the top goes down slowly but does not go up at all. How can I figure out if the motor needs to be replaced or I just need to bleed it. Or, if it some other part that needs to be repaired/replaced.

Can I get 2 Ohm Speakers to replace my 4 Ohm stock speakers?

I have a 2006 Ford Mustang and my stock speakers are blown. They are 4 Ohms and their model number is 6U5T-18808-CA. I'm not very interested in getting stocks put back in because I'm sure they will just blow again.

Can I replace the stock with 2 Ohm speakers? I have a Sony XAV-701HD Deck installed.
I'm looking for 6x8 / 5x7 speakers that have good sound and pretty good base. The sound quality is more important. I don't know which is better 2 or 4 Ohm. I feel dumb asking this question, but thanks for your help. I would consider getting component speakers.
If I wasn't detailed enough in my question reply with what I need to elaborate on!

My price range is 100-200. 200 only if they are really nice speakers.

Could you guys/gals give me some suggestions on what I should get? A link or anything helps