.dat is an utterly generic extension (.bin is probably the only better example of such a thing) used by often half a dozen completely different formats within a single game.
Without knowing what game, what system and whereabouts in the game, also what it does if you know that, you are robbing us of potentially vital information that might be used to decode it.
Payment is also a trick thing in ROM hacking circles -- money makes lawyers perk up and that is the last thing most ROM hacking communities want to attract the attention of.
Anyway took a look.
See an awful lot of German text in ASCII form, indeed that might be most of the file.
At the end of the file are a bunch of error messages in English dealing with electrical motors and car/vehicle information, and the rest of the file once I dumped the strings/opened it in a text editor appeared to deal with car/vehicle electronics and related concepts.
To that end I would be surprised if this anything we particularly deal with around here, that or mechanic simulator 2020 is far more advanced than previous efforts. The car electronics forums out there often do good work so might be better to the go look there.
At the same time if it is messing with things on the CAN bus and possibly programming devices in then be careful editing such things as frying your ECU or having to have it programmed by a big boy tool because your hacked up thing crashed halfway through programming is seldom fun or cheap.
Fire it through https://www.fileformat.info/tool/hexdump.htm
if your computer does not have a nice means of displaying text strings in files.