Ken Livingstone's proposal to introduce a £25 congestion charge band for vehicles emitting more than 225 g/km have been exposed as ridiculous following news that BMW intend to launch a new version of their £40,000+ X5 - the definitive "Urban 4x4" - which will escape the increased charge.Meanwhile, quite modest older petrol engined cars such as the 2003 VW Beetle Auto, will have to pay the huge new "Gas Guzzler" charge, and if they live inside the zone they will lose the residents' discount and have to pay the full £25 a day.The ABD's Chairman, Brian Gregory, said today: "This must be worst tax proposal in Britain. The BMW X5 is exactly the sort of vehicle that Ken Livingstone wants to target with his draconian proposals. Campaigners like Sian Berry have successfully lobbied him for the "urban 4x4" to be penalised in this way. She must be incensed that all the time spent harrassing owners of such cars and lobbying for this completely unreasonable charge has been deftly side stepped by clever German engineering. My heart bleeds."Far more incensed will be people strugging with heavy mortgage payments in Central London, who can't afford to buy a new BMW X5. They will probably be driving five year old petrol engined saloons with automatic gearboxes - Mondeos and the like - or maybe an older VW Beetle, which used to have versions that tipped just over the 225g/km threshold.These people will lose their residents' discount and will have to pay £25 a day, while their wealthy X5 owning neighbours get away with 80p.The Stern report, commissioned by the Government, suggested that £44 per tonne is an appropriate level of taxation for CO2 emissions.Motorists already pay for their carbon at FIVE TIMES the level of the Stern recommendations - in fuel duty.Now, Ken Livingstone intends to pick on a small number of people and charge them up to ANOTHER THREE THOUSAND FIVE HUNDRED TIMES the amount of tax that experts suggest is reasonable.Have we found the most unfair, unreasonable and disproportionate tax ever proposed in Britain?The ABD thinks so - and the fact that buyers of brand new £40,000+ BMW X5's won't have to pay it is enough to drive us all to take a taxi. Until you realise that London Taxis tend to be automatics, which all emit well over 225g/km - and they dont have to pay the charge at all!