So I tried searching on MTS but I couldn't find it, also searched on google and it didn't show up. I'm talking about the GUID code of a firetruck (if it's even possible and useable) because I want to use it in my custom career but don't want to get a CC firetruck so my custom career wouldn't be dependent of that custom content creator. If any of y'all know what code is it or where should I look specifically then I would be grateful.

Download this GUID spreadsheet- it's in there:
https://www.picknmixmods.com/Sims2/...MaxisGUIDs.html

Thanks to whoward69 !

I use an alphabetically sorted GuidIndex for Sim PE 0.73. It is faster to browse and doesn't require Microsoft Office 2007.

http://j7n.sytes.net/misc/sims/guidindex.txt.rar

whowards doesn't require Excel, it works with any free spreadsheet program, including Google so it can be saved in the cloud.