Sorry to be a buzz-kill but I agree ^^
I'll express this as a logical syllogism:
One must not take out loans to buy toys.
A vintage Porsche is a toy.
Therefore, one must not take out a loan to buy a vintage Porsche.
Lending institutions tend not to loan money on cars more than 7 years old. That means you are into "personal loan" territory with attendant higher interest rates. It seems unlikely that you own a home at age 19, and I would NEVER counsel anyone to take a home equity loan to buy a car. That is just dumb, and is in large part the cause of the recent "financial crisis".
As much as it seems unfair, and smacks of "old guys" being jerks and telling teenagers what to do, if you look at this objectively, it makes no sense to take a loan to buy a 15+ year old car that is likely to require significant maintenance and repair. Why not keep driving the Escort and keep saving? You could get a nice '85-up 944 for $7K or less and have a very nice driver, or pick up an SC or early Carrera 3.2 for $12-17K and go that way. But taking a loan to buy an old car is just setting yourself up for future financial pain. SAVE THE MONEY UP AND BUY THE CAR WITH CASH. You will need future cash flow for insurance, gas, maintenance, repair and upgrades. Don't spend that cashflow on a car loan.
I got my first Porsche at age 38. I had a '72 Datsun 240Z given to me as a teenager (value $2K) and over the next 20 years probably spent $12-15K on it (that's just in repairs, maintenance and upgrades, not counting insurance and gas)... sold it last February for $9K and bought my 911 right after that. Best decision I ever made, I'd been out of school and working for 15 years and felt like I'd earned it.
Anyway, best of luck with whatever you decide, I have a feeling you'll do what you want regardless of what a bunch of old dudes on an internet forum have to say...
Cheers
d.