I purchased a 2016 Sonic RS this past spring. I got it with the Chevrolet Turbo Stage Kit which adds 10 HP and 15 LBS TQ. The stage kit comes with a performance exhaust and the tune to add the HP and TQ. The first update I did was to replace the gold bowtie to black.
My next update was a few days ago adding the K&N Typhoon CAI.
Now I am waiting on a Trifecta tune so I can take max advantage of the K&N CAI and gain, according to Trifecta, more than 40 HP. Now this would be 40 HP over the base HP of 138, not over the 148 since the Trifecta tune will override the Chevy stage tune.
My next plan is to upgrade the wheels. I want black wheels.....my wife calls this "Murdered Out". I will go with wider wheels and tires for more traction in summer and keep the stock wheels for winter.
Not so sure I will do much more after that, we'll see. The car is fun considering I drive a 2012 Camaro and a 2015 Silverado.
What makes the Sonic RS fun is that I feel comfortable pushing the car to it's limits, even if it's not as fast as the Camaro. But it is hard to push the Camaro to it's limits because....well, the limits are so high and when you do pass the limit in the Camaro, speeds are much greater and there is a lot more danger if you #$%@ it up.
So in some ways, I find the Sonic more fun to drive. It's the same theory Car & Driver has on the Miata.......it's a fun car because of how it drives, but it's not a fast car.
A couple of things I wish.
I wish there was a MyLink compatible head unit that kept all the MyLink functionality while giving my Android Auto and some other features.
I wish I didn't have to have a front license plate because it covers a good chunk of air going into the intercooler. I might figure out how to move it out of the way.