Car Valuation Experts Warn Over Modifying a Vehicle: Here’s Why
Modifying a car can be a way to express personal style, but valuation experts are warning motorists to avoid major changes. Such modifications can lead to a dramatic increase in insurance premiums and a reduction in the vehicle’s resale value.

Experts warn against car modifications that could negatively impact resale and insurance.
How Modifications Affect Purchase Price
Most car buyers prefer unmodified vehicles. Even cosmetic changes can negatively affect a car’s value. According to cap hpi, poorly executed paint jobs, body kits, or decals significantly reduce a car’s appeal and value. Jeremy Yea, senior valuations editor at cap hpi, says that modifications are “typically designed to suit the taste and style requirements of the original owner,” which can reduce the overall market appeal.
Engine and Performance Modifications
Engine modifications, such as ECU remaps or larger turbos to increase the bhp output, can raise concerns about potential reliability issues and maintenance costs. Unauthorised or non-original aftermarket parts can decrease the vehicle’s value due to potential risks and warranty complications. The effect of modifications on a car’s overall value relies on several factors, including the quality of the work, reversibility of alterations, and legality.
Warranties and Insurance
Non-manufacturer modifications can jeopardize warranties and impact insurance coverage if not fully declared. Many drivers may be unaware of the impact that modifications have on their insurance premiums. One example is a Fast & Furious-style nitrous oxide kit can increase the average premium by 378 per cent. Even cosmetic modifications like side stripes can increase insurance costs by 178 percent.

Nitrous oxide modifications can dramatically increase insurance costs.
How to Modify a Car Without Causing Issues
to prevent devaluing or hindering a car’s market appeal, here are some guidelines:
-
Retain Original Parts: Always retain the original parts to potentially reverse modifications before selling.
-
Focus on Performance: Focus on enhancements that improve vehicle performance rather than cosmetic modifications.
-
Professional Installation: Ensure modifications are installed by professionals who use quality parts from reputable brands.
-
Consider Long-Term Impact: Consider the long-term impact on insurance and vehicle integrity.

It’s crucial to keep original parts