the inevitable head gasket failure in the 100 K-120 K range. Very labor intensive as they have to remove the engine from the car to remove the heads on the horizontally opposed engine. If you have THAT guy do it, you might be looking at $5000+, based on those estimates.

Caveat - Although Subaru never came out with a recall or anything, I am sure they probably addressed this in design and 2010's is likely not susceptible. This was very common problem in the early 2000 models, so much that changing them out became "recommended maintenance".

Subarus are bullet proof otherwise.