My question is on SOLID principles, because I couldn't answer a question (beyond the obvious meaning of the various principles of SOLID) at an interview and it really bugs me. I have done a couple of days worth of digging around and have yet to come up with a satisfactory summary.

The question was:

If you were to look at a .Net project that I told you strictly followed SOLID principles, what would expect to see in terms of the project and code structure ?

I sort of floundered around a bit, didn't really answer the question and then bombed out. Any help or thoughts will really be appreciated.