I am of the opinion that the CZ copies (Witness) are not a good choice for defensive use. Are they reliable? Yes. Are they cheap? Yes. They lack a decocker and are thus patently unsafe, in my opinion. Every time you load it, you have to physically lower the hammer with your thumb. There is no built in way for the pistol to lower the hammer, safely. Just one guys opinion. Other people are perfectly fine lowering the hammer on a live round. I think if you do it enough times in 20 years, you are going to have an accident at least once.
Those Smith & Wesson M&P pistols, new in the box, for $299 after rebate above, are a STEAL! That is absolutely a good deal on a world class defensive pistol.
My car guns are Smith & Wesson SD9VE 9MM pistols. They are sold almost year round for $259 to $269 online, and honestly, based on everything I've seen out there, you wont find a better budget defensive pistol for the price (other than the $299 M&P above). They are 100% reliable, designed by copying the Glock design. The trigger on the new ones is about 8 pounds, and much better than the 13-14 pound triggers on the older Sigma models.
If I was looking for a car gun, the M&P or SD9VE would be at the top of the list.