Readability Tip #1

Better If

var myCar = new Car({color: 'black', style: 'Police Car'});
var theirCar = new Car({color: 'red', style: 'Sports Car'});
var isRedSportsCar = theirCar.color === 'red' && theirCar.style === 'Sports Car';

if(isRedSportsCar){
  myCar.chase(theirCar);
}

Ugly If

var myCar = new Car({color: 'black', style: 'Police Car'});
var theirCar = new Car({color: 'red', style: 'Sports Car'});

if(theirCar.color === 'red' && theirCar.style === 'Sports Car'){
  myCar.chase(theirCar);
}

Abstracting out the conditional logic into a well named variable will greatly increase readability of your code for other programmers or your future self.