In the uk if i modify my car exterior and interior completely would it be cled as a kit car?

this idea came to me through top gear jeremy clarkson modified a toyota mr2 interior and exterior and by the time he finished it was totally different it look like a mini ferrari now the insurance company said to him because he's modified the interior and exterior its cled as a kit car i just want to know this for sure as i have a bmw 316i that now looks like a nissan skyline r34