What's the deal with the Porsche coolant? What properties does it have that it is required in the new motors and what not?

No phosphates or sulfides?

I'm sure there's an aftermarket equivalent. My VW calls for special coolant and I replaced it with the orange Prestone 5/150 extended life stuff. I've had zero corrosion. Make sure you mix coolant with purified water. I think the Valvoline G-05 is supposed to be the new hot stuff for aluminum engines.

http://www.valvoline.com/pages/products/pr....asp?product=10

it's liquid?

Nope...it's water based.