There is no CAN bus on the Mk3 or Mk4

They connect to the ibus or kbus (depending on vehicle)

What do you want to do?

hi
yes, I know that mk's system use iBus or kBus, but my question is if ther's some expectation about Canbus system...so it can be fake at same mode as we can fake now on mk system...
If I would to change screen on a E60 how could I do?

To change screen on E60:

1. Sign yourself up as a BMW dealer
2. Puchase the diagnostic equipment
3. Update the software in the car
4. Whilst updating, capture the data, analyse it, and modify it
5. With the modified data, reload software on your car

To do all the above you need
a) to be a software engineer
b) to have the skills and resources
c) to have the money

Is changing the screen worth the hassle?

The software is only updated via the diagnostic port, and is done via an online authorised connection to BMW
So without the equipment etc there's not much you can do...

...unless you want to open the have, extract the data from the EEPROM, modify it and reload it. But you need to have electronics experience as well as being a software engineer

Are you up to it?

ok, thanks...I'll take my screen as is...