Firstly, "must do" is a bit strong and a bit of a pisstake of the clickbait Youtube videos out there. With that said I do strongly recommend them if you can to get the best performance out of you car and extend it's life. I've arrived at these recommendations by comparing the 144001 directly to the car it was copied off - the excellent LC Racing EMB-1h plus basic fundamentals of rc car operation of which I've been around for years. 

1. Fill (or empty) the fluid in the shock absorbers to the correct level
After a lot of feedback to the community, WL toys has started filling up the shocks with oil but now isn't too little but too much they are putting in. Too much oil in your shocks means that the shock cannot be fully depressed it will ultimately force the oil past the orings and in doing so damage them. The fix is easy and if you follow the method below you won't need any extra oil to top it up.

Remove the shock from the car by unscrewing the lower philips screw and upper lock nut.

1. Remove the lower plastic shock collar and spring. Wind off the spring tensioner (optional)
2. SLOWLY unscrew the top cap by holding it upright till it comes right off and then screw it back on about half way.
3. Should should now be able to full depress the shock. Some of the oil should leak past the top cap - this is what you want.
4. Screw the top cap back on and see if you can depress the piston all the way. If not repeat steps 2-4.
5. Wipe down the shock with a rag, reinstall the spring tensioner (if you removed it), the spring and collar. Re-install and complete for the 3 other corners. Note: while the shocks are off consider doing the diffs (below) as well.

Now that the shocks can fully compress it allows the spring to do their job properly. I found with the stock setup I needed to loosen the spring tensioners right up on the front and about halfway down on the back for the right right height. This is a good starting point and probably the next place you'd consider with the shocks is increasing the oil weight in the back because the dampening is pretty light - probably around 60wt oil would be ideal.

This review and advice article covers the use of the surpass hobby/racerstar/goolrc brushless ESC programming card which can be used on most in not all power systems from these suppliers. It is a simple <$10 device that allows you to easily change the parameter of the ESC.

One of the easiest ways to upgrade your brushed RC car is to change the brushed motor and ESC with a brushless ESC and motor as I did here with the Surpass Hobby 3650/ 60a ESC combo (click here to see full review). If you are lucky like me the drive train (gears, differentials, driveshafts) are designed to take brushless power but even if you don't there is a way to tame you power and still get the benefits of fast acceleration, higher top speed and better battery life. This came as a surprise to me as I thought the $40 combo I bought surely wouldn't have this functionality.

There are several cards that can be used to program these ESCs but the one I recommend is the Racerstar LED Program Card that works with all of the ESCs and motors branded as surpass hobby, goolrc, racerstar and probably more. For the record I accidentally bought the surpass LED program card for brushed crawlers and after initially thinking I couldn't use it it turns out I can, more below.

Sorry for overly long title. I've now had the Surpass Hobby 3650 sized 3900kv brushless motor and 60A ESC Combo for about 3 months now and have thoroughly tortured it in a very large 1/10 scale 4wd short course truck (brushed version of the DHK Hunter here) for this review. With these electronics you can easily upgrade any 1/10 scale hobby grade rc car to brushless which for the uninitiated offers significantly more power, efficiency and if done right, durability over their brushless counterparts. This stands true for on-road tourers, pan cars and offroad buggies, SCTs, trucks (2 and 4wd). The only cars this would be unsuitable for is where very fine control is required - drift and crawlers come to mind. Read on for install and review. 

A look at the gear
The kit is very simple - a 4 pole brushless 3650 sized motor (540 in brushed terms) and a 60a ESC. The motor I reviewed is 3900kv which is a good all purpose size on common 2s batteries. The ESC is another simple waterproof affair with built in cooling fan. They are both waterproof according to the specs but personally I haven't and would not put the ESC to the test. The ESC can be programmed with common features but does require this programming card to change. Parameters that can be changed are:

Instructions (click to enlarge)

The SG 1602 Brushless RC truck is a 1/16 scale 4wd off road truck/buggy (truggy) that has a powerful and efficient brushless motor/esc system. Note, this appears identical to the HBX 16889 and shares the same parts. It is available from Banggood for less than $90 and as little as $70. I've had one of these for about 2 months now and for the times that my son lets me drive it I've had quite a few runs to get a good feel of performance and durability. My full review is below.

What's in the box?
Actually this is pretty well equipped:

• The Truck (4wd brushless 1/16 scale)
• 2.4GHz remote
• 2s 1300mah li-ion battery
• USB charger
• LED Headlight system (for user to install)
• Wheelie bar (for user to install)

In order to get this running you'll need 4 x AA batteries for the transmitter. These 2.4GHz transmitter are extremely efficient so you'll get good battery life even with cheap alkaline batteries. As mentioned above there is a nice set of headlights and wheelie bar included and these are very simple to install with well laid out instructions.