Small update about steam stuff and this patch. If you want to still get Steam Achievements with your unpacked and patched version of TDU2, copy steam_api.dll from original steam TDU2 folder and place it in the folder where is your unpacked and patched TDU2 game is.
I tested this and it works. Getting Steam Achievements with TDU2 uP v0.4 patch :) Awesome!
Note: my patched game is in "Steam\steamapps\common\Test Drive Unlimited 2" (where the original was) i just renamed original tdu2 folder to something else, created new "Test Drive Unlimited 2" folder in "Steam\steamapps\common\" and placed my unpacked/patched tdu2 in it. Works like a charm!
Posting this here, because i know some of you might want to use this patch, run game directly from steam and get steam's achievements like you would on the original game.