say , if I decide not to drive my X5 for a day how much can I sell the unused emissions for .
if I hold on to my farts how much can I claim for not pumping methane into the atmosphere and can I buy some emissions when the price is low so as to relieve the pressure .
I could even strap a vacuum cleaner to my butt to capture my farts , maybe even run my X5 on the methane or would the government still charge me fuel duty and vat on my own farts ? .