We confront the new physics models with extra isosinglet down quarks in the new CP violation experimental era with sin(2β) and ε′/ε measurements, K + →π + νν-events, and x s limits. The closeness of the new experimental results to the standard model theory requires us to include full standard model (SM) amplitudes in the analysis. In models allowing mixing to a new isosinglet down quark, as in E 6 , flavor changing neutral currents are induced that allow a Z 0 mediated contribution to B-B mixing and which bring in new phases. In (p, η), (x s ,sin(γ)), and (x s ,sin(2φ s )) plots we-still find much larger regions in the four down quark model than in the SM, reaching down to η≈0, 0≤sin(γ)≤1, -0.75≤sin(2α)≤0.15, and sin(2φ s ) down to zero, all at 1 σ. We elucidate the nature of the cancellation in an order λ 5 four down quark mixing matrix element which satisfies the experiments and reduces the number of independent angles and phases. We. also evaluate tests of unitarity for the 3 × 3 Cabibbo-Kobayashi-Maskawa submatrix.