The feature is sold for much less than $2K. In the article it mentions $400 for a lifetime subscription. What could be attractive to that executives is an opportunity to broaden the market for this feature.

I.e. instead of having only one chance to sell you this feature at the time of order, they now can let you trial this after the purchase. They might even run a promo during a cold streak for free (just like SiriusXM gives free access during major holidays). $18/mo is there just to make $406 number more attractive.

I think people are too distracted by the subscription aspect and missing the fact that the "conversion rate" for heated seats purchases could be improved.