Menu selling is used by the majority of dealerships in the US for several reasons
One of these reasons is compliance, most, if not all, dealers in the US are under tight surveillance by local and federal law makers to protect consumers against any violations of their rights and/or protection against bad business practices. Here in Canada, this currently is not a problem but, it may be a sign of things to come and with an implemented menu selling process, most compliance issues are already covered.
Another reason menu selling is so popular in the US is that it's very profitable. Dealers who are not menu selling, on average, sell far less than ones who use a menu. Electronic menus, as opposed to hand written paper menus, offer even more assurance that all products are being offered to all customers--which in turn will generate far greater profits than traditional step-selling.
Menu selling is the way of the future.