I assume you have Global Entry as that will affect how quickly you're out on the street. With carryon, it usually takes me 10 - 15 minutes with GE to make it to the curb. Mostly it's the walk time. So IF your flight arrives on time, you should be at the curb around 3:30, assuming no problems with GE.
Travel time, curb to cub from LAX to SNA is around 45 minutes in ideal conditions. Leaving LAX at 3:30 is far from ideal, as you'd just be dumping into the start of peak traffic. Normally it wouldn't be pretty, but it being Christmas week could change the usual traffic pattern a lot. There might be less traffic, but with people off, more would be in the HOV lanes (you see this on weekends). In all, there are a whole lot of unpredictables to this.
My estimation is that you'd have about a 50% to 60% chance of pulling it off.