Austin Williams responds to Ken Livingstone's objections to a reader's letter about London's Low Emissions Zone.
Pat Devereux drives the Honda FCX Clarity, while Andrew English wonders why Californians seem to get all the best green tech.
Rebecca Feiner meets the unlikely stars of Discovery Channel's Chop Shop series, who transform wrecks into bizarre masterpieces.
Honda has launched what Andrew English thinks is the most significant car of the year, the FCX Clarity.
Peter Hall addresses criticism of last week's article about offical road safety policy.
