Kelley Blue Book’s Senior Managing Editor Matt DeLorenzo writes This Week in Car Buying, a weekly column on KBB.com. In this week’s article, Matt discusses the deals and incentives that manufacturers are using to gear up for the spring selling season. The March 1 days’ supply figure of 78 reflects slightly softening demand more than production far outstripping demand. Tesla changed its mind after announcing that it would move to online sales only. And, Kelley Blue Book data shows that buyers seeking new-car bargains less than $20,000 will see their options continuing to shrink.