I borrowed some money from a family member, and then paid her back within a month as my money was tied up for that month.
The way I see it, I would never take a loan etc out for a car. My mortgage is more then enough!
I spend about £200 a month on fuel.
No mods just yet, as I dont want to do anything that affects my warranty etc.
I do have a credit card to clear from when I had some home improvements done, but I only used a card since it is 0% until June 2010. I'll clear this card by Nov this year though I reckon.
Once thats all clear and Im debt free (other then mortgage) I'll buy some OEM upgrades, like the RNS510 etc

At 19, your insurance may be quite high - so check that before you buy a car.
Also you need to keep money to one side, in case any repairs etc are needed for the car (you never know!)
Servicing etc is also costly.
If the car is out of warranty etc, you'll need to spend even more on any possible repairs, and MOT etc.