This post is in relation to the Tesla warning that its rate of expansion will be “notably lower” this year and the recent price cuts they've made to keep sales

This post is in relation to the Tesla warning that its rate of expansion will be “notably lower” this year and the recent price cuts they've made to keep sales going. In relation to that, "building better cars" means building cars that sell more - either having the characteristics/features that people want and are willing to pay for or making them cheaper.