Not my choice, but what I've got.

I purchased an '03 A4 1.8T Avant through a local broker. Car had 69,500 miles, reasonable price (right around KBB/private seller). Everything else about the car appears mint, and my independent mechanic checked it out and said everything is in good shape except the turbo, but the turbo was bad from the get go, and completely failed within a few days.

Broker took it back and put in a new turbo, no charge. I was poking around in there this weekend and figured out it's a JDM Sport K03 turbo. One of the ~$200 E-Bay specials.

I've got about 700 miles on it so far. Seems to deliver full boost as far as psi goes (approximately 10psi), makes an audible whine (not so much the "dentist drill" sound, yet). I don't have a frame of reference for performance, as this is my first Audi.

I'm inclined to just drive it. I'm not an aggressive driver, I'm not racing or really pushing the car. Is this a mistake on my part? Can I ruin my engine if this JDM turbo is a POS and falls apart/seizes up?

What's the worst that can happen? What's the best I can hope for?