Petition Make Road tax FREE for all classic vehicles over 25 years old

Currently this is only available for vehicles that were registered before 1973 - This petition would make it a rolling 25 year term - this would mean that now vehicles registered before 1986 would benefit from free road tax, therefore reducing the cost of keeping classic cars on the roads.
Firstly this would not be a huge revenue loss for the DVLA as there are not that many roadworthy 25 year old plus vehicles on the road today.
Secondly these vehicles are mostly second cars, mainly used at weekends and therefore they don't cover huge annual mileages, so why should they pay full tax when they may only be used a few days a year.