Indeed, the 8 year old rule is just idiotic to say the least when we have vehicles manufactured in the 60s still operating in the road.
Uganda and Tanzania do not have the 8 year rule yet when you drive on their roads their vehicles do not seem more beat-up than ours.
KRA should just introduce a flat tax for each make of vehicle no matter the year of manufacture, perhaps that would encourage people to buy new vehicles, and locally assembled vehicles should be charged even less.
Right now what we have is some chaotic system, the more popular the vehicle, the higher the taxes. The fellows at KRA usually wake up in the morning and decide to arbitralily increase taxes on whatever make is more popular in the market. I think a 8 year old Allion now attracts 5000 dollars in taxes.