2011 Forester = engine rebuild?

Our 2011 Forester has an internal engine leak and needs new breaks and
transmission lines.  The original quote for service was $2700 to get the engine
out and really pinpoint the extent of the problem and $8000 for parts and labor,
including rebuilding the engine.  The car has a little over 100k miles. We still
owe $8000 on the loan.  Is it worth it to do these repairs, or would it be more
prudent to look for a new used car in the 10k mile/$50k range and have them
roll the existing loan balance into the new loan?  My concern is that we put this
$10k into the car, and then other things start going due to regular wear & tear
and we end up putting way more money into it than it's worth.