CAR and truck owners who modify their vehicles without telling the Department of Transport face the prospect of having their vehicles seized and being summonsed to court.
More than 50,000 changes to vehicles were made in 2011, ranging from simple cosmetic changes such as adding a spoiler and changing bonnets, to removing seats, lowering a car's suspension and adding axles to a heavy-goods vehicle.
Unlike other EU member states, there are no rules in place in Ireland that regulate modifications, including ensuring that parts used are safe and appropriate for use.
The RSA is planning a new regulation system and is considering two options.
The first is a self-declaration system, where the vehicle owner would be obliged to notify the Department of Transport of any changes and state that they were both appropriate and legal.
The second is an approval process, where the vehicle owner and mechanic who carries out the work notifies the department and declares the work is safe.
Under the latter option, the modified vehicle would have to undergo an inspection and/or roadworthiness test, before being declared road legal.
The RSA said the changes were needed because modifications which alter the strength of vehicles, such as adding seats, or installing 'bull bars' or bonnet scoops can change how the vehicle performs and can also cause more serious injury to pedestrians or cyclists if involved in a crash. Other changes, such as changing the suspension, cannot be seen by gardai, which makes enforcement difficult.
"All road users should have assurance that vehicles, when modified, are not rendered unsafe and that the modification has been completed to an appropriate standard," it said.
"Some vehicle modifiers adhere to the original manufacturer's guidelines and follow good engineering practice.
"However, roadside inspectors have indicated that many substandard vehicle modifications which pose a threat to the driver and other road users currently exist.
"If a modification does not adhere to guidelines, then the vehicle should not be allowed use a public road."
Existing legislation is "lacking" provisions to cover modifications, unlike the UK, Australia and New Zealand, which have safety checks in place.
Dangerous vehicles are considered a contributory fact in 1pc of all fatal road collisions.
According to the RSA, penalties should be imposed on drivers who fail to declare their vehicle has been modified.
They include seizure, and a court appearance with penalty points on conviction.
The seized vehicle would have to undergo safety checks before being released, at the owner's expense.
The RSA is inviting public submissions on the changes.
The consultation document is at www.rsa.ie, and submissions should be emailed to firstname.lastname@example.org by March 20.