Why do I have to pay tax on my state pension when I paid tax on my serps and stamp throuout my working life? Isn't this double taxing?

Phil, Warrington, England

I n Sundays article on car tax it said that pre 2001 cars will pay a flat fee of £200. As it stands at the moment there are 2 levels of tax for pre 2001 cars. The aticle implies that there will only be 1 level is this correct.

Andrew Heggie, Preston, Lancashire

I understand there to be a Road fuel tax credit system for biodiesel suppliers, every litre sold qaulifies for a tax credit valued at up to £0.15 pence per litre.

Can you explain this system to me, in particular how can these credits be traded? Are there any brokers who will trade them?

John Walsh, Tadcaster, UK