If you find something that's been taken care of then I wouldn't sweat 100K miles. The 4.6 engine in the '99-'04 GT's is pretty durable and reliable given that it's not been abused or neglected.
As far as spending $20K or $6K, I think your old man already gave you some decent advice on that. I don't know what your situation is nor is it any of my business, but figuring you're a typical 19 year old then that means your finances are limited and you'll have some sort of college to deal with soon if not already. I get the sense that the "$6K" number you and your dad came up with means you'd be buying a car outright rather than financed?
Let's look at if you finance a car.... $20K sale price, subtract your $6K as a down payment. Financing $14K (plus tax/title/licensing fees) on a 5 year term will be about $325/mo assuming you get a decent interest rate. Insurance, you need to call around and get a few quotes but a guy your age I don't see it happening for much less than $150/mo - I'm almost twice your age with a clean no-points driving record and full coverage insurance on my '01 is still about $100/mo. So now we're at $475, every month, just for the privilege of admiring how it looks parked out in the driveway - you haven't even put gas in it yet. BTW, I'm giving you what I think are pretty low numbers, and wouldn't be surprised if it were notably more.
If you think that sounds realistic then go ahead and get a $20K car.
If you see any '99-'04 GT's etc. that look interesting then feel free to post a link to the ad and we'll be happy to give our input.
As far as spending $20K or $6K, I think your old man already gave you some decent advice on that. I don't know what your situation is nor is it any of my business, but figuring you're a typical 19 year old then that means your finances are limited and you'll have some sort of college to deal with soon if not already. I get the sense that the "$6K" number you and your dad came up with means you'd be buying a car outright rather than financed?
Let's look at if you finance a car.... $20K sale price, subtract your $6K as a down payment. Financing $14K (plus tax/title/licensing fees) on a 5 year term will be about $325/mo assuming you get a decent interest rate. Insurance, you need to call around and get a few quotes but a guy your age I don't see it happening for much less than $150/mo - I'm almost twice your age with a clean no-points driving record and full coverage insurance on my '01 is still about $100/mo. So now we're at $475, every month, just for the privilege of admiring how it looks parked out in the driveway - you haven't even put gas in it yet. BTW, I'm giving you what I think are pretty low numbers, and wouldn't be surprised if it were notably more.
If you think that sounds realistic then go ahead and get a $20K car.
If you see any '99-'04 GT's etc. that look interesting then feel free to post a link to the ad and we'll be happy to give our input.