We mean works as in it does stuff like move and light up. It doesn’t suck gas. Proving that with enough time, Lego pieces and will, you can make anything, some guy made an actual Lego V8 engine. It took 4 months to complete.
Which is probably why GM and Ford choose not to use Legos. Plus Lego cars are super heavy and hard to sit in. Plus next thing you know, you’d have Lego and Duplo monopolizing the car market and that wouldn’t be good. Still I suppose they could arrange for the outside of 50% of Lego cars to have the bricks facing inward and half facing outward so that when they crash, they have a 50/50 chance of either crashing or interlocking which should be safer.