you sure this isn't just condensation?
you will get this loads fella, bigger the bore on the exhaust, the more you will get.
i get loads of comments about it on my project car, and it always clears up after a few minutes idling, or a couple when driving.
just keep an eye on coolant level and engine temp, go for a spin for ten mins or so, then look at the exhaust and be happy it's cleared up, if not H/G or turbo failure iminant.
also, bear in mind it's colder out now, so even more condensation will settle in your exhaust