For interests sake, absolute top speed with speed limiters off is set to 180 KPH.
Which is kind of crazy as the tires would explode in RL scenarios, that is the very reason racing trucks are limited to 160KPH\100MPH. Tire technology can't keep real physics and centrifugal forces from expanding and exploding tires at any greater speeds than that.
There is also a new mod out for the big Mercedes, gives you the chipped "black" engine at 670HP. This engine really sparkles, it has good response from throttle at all settings, revs like a banshee.
And for Cherio, and the rest of us gear jammers, there is a new mod out for the ZF 16 speed transmission, I'm hoping to be able to mod it for all the rest of the trucks soon, currently only for the small 310HP Iveco rig.
As for bonneted models, probably won't see them yet, it seems the people at SCS are still busy with bug hunting etc, pity really because I'd love to run a nice Western Star or similar.