POLICE: Car lot owner chases down, shoots suspects who stole car from his business

This incident was in Texas, and Texas law allows the use of deadly force in defense of property, if I recall correctly. This is not the case in many states, unfortunately.
A car =/= a horse in the terms of the laws, although stealing someone's car today is easily as bad as stealing someone's horse back in the days when horses were the primary means of transport. Laws should probably get an update to reflect this.

In many cases, in those days depriving a man of his horse a horse at the wrong time was a death sentence. Horse thievery was a capitol offense. That's why cattle rustlers were put in jail, but horse thieves were hung. I love my car, but I can't say it's a capitol offense to steal one.

Even if he isn't charged, things like that give gun-owners a bad name.