How long do I have to pay premium tax?

Currently my road fund licence is £600,00 per annum how many years will I have to pay this high rate of road tax for? Does it fall to the normal level of road tax after this initial period?

Should I get a petrol or diesel SUV?

I'm considering buying a Mercedes-Benz GLB but I'm yet to decide which option is better, the 200 petrol or the 200d diesel one. I'm a normal all-round driver (driving on both motorways and in the city)....