Isotope Green (Lemon Yellow - Europe) will mark the first time a limited-edition Beetle is available with the TDI engine. In fact, Isotope will be available in every possible GLS configuration — 2.0 gas, TDI diesel, 1.8 turbo; automatic or manual transmission; along with various options such as a power sunroof, heated seats and foglights. Unlike Europe's 'Panama' interior, American customers will have a choice of either black or grey leather for this special model. The non-metallic Isotope Green is this spring's limited-edition color.