If you turn up to a Police station they may be too busy to check your car. Talk to them first and ask when is convenient. If they are not too busy they may check it over for you. The fire department may be a better choice.
When travelling if a police officer inspect how it is fitted and it is unsafe they are empowered to prosecute the parents. The most likely fine is for a child car seat not suitable to the weight or height of the child. Depending on the severity it is likely the police will warn and advise before giving a fine.