How do you test that it doesn't work? I see you're sending an IS_MTC packet which won't work via InSim Relay unless you connect to the host with the correct admin password using the IR_SEL packet.
Only a subset of InSim packets are allowed to be sent / received:
For the whole documentation, see the original InSim Relay thread by Victor:
Some people use LFS Editor to create the entire 3D model, others use Blender to create the 3D model, then export it as an OBJ file, which can be then imported into LFS Editor.
Motorcycle gearboxes are a bit different - you must shift down in order to get into 1st gear.
Once you get going, you will notice that at low speeds, you control the bikes handlebars directly, but once you get up to speed, you control the lean of the bike instead. This means you need to be more gentle with the steering and start steering a bit earlier than you'd expect.
Actually communicating with InSim is the easier part You listen for specific packets coming from LFS telling you about the current state of the car (speed, acceleration, position etc.) and then send other packets telling the AI car what to do (turn the wheel, accelerate, brake etc.) in regular intervals like every 100 ms.
I've got a very early prototype where I tell an AI car to drive at a constant speed using a PID controller:
I haven't worked much on the driving lessons layout, but I've got a server running called [WIP] City Bus Driving where I've started working on a traffic driving layout primarily suited for buses, with the help of a few other players.
For driving lessons style server, I suggest joining [RL] Real Life 1 where you have to take some driving lessons and take a test before you get a driving license.
Modelling proofs belong to a thread in the Work in Progress forum, which you then link in the mod submission form. I have moved this thread to the correct forum in the "Development thread URL / ID" field.
Thanks for posting this, I think he explains everything very well and in detail. I also recommend watching his videos on suspension where he talks about roll centre. This might be helpful for people building suspension for their mods.