Most people on benefits are only on them short term and many of them have cars, bought when they were in work and needed to be able to get to and from interviews and job, once they are back in employment. Having a driving license and car is essential if you want to work in many rural areas or towns with a high level of unemployment when public transport is minimal and you have to travel to work.
A single person gets £73 a week plus Housing Benefit and Council tax benefit and that sum has to cover everything. Some people on benefits are tempted to work on the black. I do not mean those holding full time jobs and claiming benefits, but ones who will do the odd day here and there as opportunity to get an extra £100, cash in hand and not report it. And who can blame them. Apart from anything else, the benefits system is so cumbersome if the worker reported it, their benefit would be stopped and it would take weeks to get it reinstated - all for one days work and £100.
There are lots of urban myths about 'benefit scroungers'. There are relatively few of them, but those that are make good media.