IF the Government finds it difficult to increase police wages to a liveable amount, then, IMHO the immediate and easy solution is to keep realistic on-the-spot fines to a level where you can check these corrupt police to only line their pockets with sums which are not hard on the average pocket and easy to pay and finish the matter immediately.
i.e. an official fine of 1000 baht for things like no helmet, e-cigs, no seat belt, and other such minor offences would probably result in an un-official payment of around 500 baht to the cop, enabling him to reasonably supplement his income, and also not be too stressful on the violator.
IMO, the e-cig extortion mentioned in this post only took place because of the ludicrous penalty imposed by the Government which is a maximum of 500,000 baht and 5 years in prison, for an e-cig possession!!!!