DVSA sometimes have a multi agency checkpoint which can be at any random location.
It may include Department of work/ pensions DWP, HMR& Customs and a CVU commercial vehicle unit police .
DWP have hand held computer tablets and can check pay from your National Insurance number.
It has been known that CSA child support agency have caught up with non payment of arrears .
So be careful of trying to hide other work/jobs.