These changes will be back-dated to become applicable from 1st January 2004. 
This will effectively ban virtually all tinted films fitted to windows forward of the B-Post on any vehicle that is to be driven on UK roads. 

There has also been a great deal of debate in recent years about the legitimacy of window tints that do not obscure the vision of the driver. A clear case has been argued that road-safe window tints do not actually conflict with existing regulations. The Department for Transport have argued however that Section 32 was always intended to cover materials attached to the glass, despite the fact that no mention of this is made in the Regulation itself.

The only solution remaining would be to amend the Legislation.

Consequently and in order to clarify the situation, the Government have finally decided to up-date the Regulations to specifically include Tinted Films since, in the view of the Police and the Department for Transport, this is the only way in which the problems of excessive tints can be remedied.
Unfortunately however, even tint films that may be considered to be safe for road use will now be viewed as in conflict with the Regulations, enabling the Police and Vehicle Inspectorate to take action against vehicle owners.
This has significant implications for the owners of vehicles that have window tints already fitted and also those that are responsible for installing or selling window tints.

Implications for the vehicle owner

After much discussion, a sympathetic Enforcement Policy has been agreed between the Department for Transport and The Glass and Glazing Federation to ensure that all vehicle owners that have had tints applied in the past may be dealt with fairly. This applies in particular where the infringement is with respect to tints that do not pose a significant threat to Road Safety, despite being in contravention with the amended Regulations.
In any event, after the date of the amendment to Section 32, the owner of a vehicle that has window tints applied forward of the B-Post could be challenged by either a Police Officer or by an Inspector from the Department for Transport’s Vehicle Inspectorate, where their vehicle is noticed being driven on Public Roads. 
Where such a vehicle is stopped and the window tints applied are such that the Visible Light Transmission level, when measured using an approved device falls to below prescribed levels, the following enforcement guidelines have been agreed with, and recommended, by the Government.

Above 30% Visible Light Transmission (Less Severe Window Tints)

The owner or driver of such a vehicle would be required to have the tinted film removed from the windows under the direction of either a Rectification Notice or a Delayed Prohibition Notice. A period of grace will apply for a limited number of days (normally ten) during which time the vehicle may be driven whilst the rectification work is to be completed. 

In either case, the vehicle will need to be inspected by either a Police Officer or Vehicle Inspectorate Officer to confirm that the glass has been restored to a compliant condition. Prosecution is unlikely in such circumstances provided the vehicle owner complies fully.