If you are using a passenger vehicle either charger will work. If you are using a specializied commercial, industry, or military vehicle that works on a 24volt system (you will know if it does or not) then the first adapter is the one that you need to use.
However...
I would not use either of these. 3rd party power adapters are notorious for being of poor quality and could be dangerous to not just your Mac, but to you as well. If this is for your car, I recommend getting a DC power inverter and a GENUINE Apple Power Adapter
You are connecting an Apple laptop worth thousands to a $30 adapter....to me, it's just not worth the risk. The second benefit is that you will have standard AC power outlets, meaning you can use them for just about anything you would plug into your home.