The legality of customizing exhaust tips for road use depends on various factors, including the laws and regulations of the specific jurisdiction you’re in, as well as the modifications you’re making.

In many places, modifications to the exhaust system, including the exhaust tips, are subject to regulations aimed at controlling noise levels and emissions. Here are some general considerations:

1. Noise Regulations: Many jurisdictions have laws governing the maximum allowable noise levels for vehicles. Modifying the exhaust system in a way that increases noise beyond legal limits may result in fines or penalties.
2. Emissions Regulations: Altering the exhaust system could potentially impact emissions performance. In regions where emissions testing is mandatory, modifications that affect emissions may result in a vehicle failing inspection.
3. Visibility and Safety: Some modifications, such as excessively large or protruding exhaust tips, could impact the visibility of other drivers or pedestrians and may pose a safety hazard.
4. Street Legality: Some modifications may not be explicitly addressed by regulations but could still be considered illegal if they are deemed to pose a danger to road users or if they violate broader laws related to vehicle modification.

Before making any modifications to your vehicle’s exhaust system, it’s essential to familiarize yourself with the relevant laws and regulations in your area. Additionally, consulting with a knowledgeable automotive professional or legal expert can provide guidance on whether specific modifications are legal and safe for road use.