[AlexBp]

because when people with undeclaired mods have accidents they tend to end up getting theur insurence invalidated and the repairs are done with money from the insureance pot so to speak

and the pot is funded by other peoples payments

plus they generalise types of cars
"oh we get sons of saxos with undeclaired mods we will bump their premiums up to fill the pot"

its frustrating when (and im not accusing you here as youve said you wont put it on the road) people openly admit they arent declairing their mods and laugh about it