Those "no-box" AMP NM connectors they use in modular homes are also IDC connections. You can bury them behind the drywall according to U/L. There was a time when AMP was saying you could use them in general wiring, fished etc. The code didn't change (334.40(B)), only the marketing.
It always smelled pretty fishy to any inspector I talked to. I talked to an AMP rep about it and he sent me a few. (I may still have them around here somewhere) They are not much different than the Scotch Lock in my opinion. The last time I saw an ad they were only targeting modular homes and citing 552.48(N) and similar.
