Fredo,
Sub 225g CO2 band would certainly be nice, would make it the only full size SUV in that band, as you said a nice competitive advantage although I am sure Ken would find a way to them slap a 4X4 tax only no matter what CO2 is, since he has already said the Lexus RX 400h won't get the Hybrid exemption anymore...
I am sure BMW will try to roll out brake regeneration and other tweaks to take it as low as possible alternatively they should move the upper band to 250g
I agree with ISUK on the fact the market offering is getting out of control and that is the biggest factor the residual front. Look at the R class, that thing is impossible to sell, The GL is nice but too big for the UK and the ML is toast with the X5...The X6 seems to me it is an answer to a question nobody has asked. The smaller SUV makes sense and the X3 has had great success but there are only so many niches the market can take as far as SUV go...
C