248. Where the consideration paid or payable by a registrant for an improvement to a passenger vehicle of the registrant increases the cost to the registrant of the vehicle to an amount that exceeds the amount deemed under paragraph d.3 or d.4 of section 99 of the Taxation Act (chapter I-3) to be, for the purposes of that section, the capital cost to a taxpayer of a passenger vehicle in respect of which that paragraph applies, the tax calculated on that excess shall not be included in determining an input tax refund of the registrant for any reporting period of the registrant.