Cars and more are errors

[T2trixe]

Try to unsub all the contents and verify the game. (after successfully verified you can add the addons again)
Steam - Library - right click Garry's mod - Local Files - Verify Integrity of game files...

as well as that. try downloading from here all the game contents from:
Half Life 2 Extras | Half Life 2 Episode 2 | Half Life 2 Episode 1 | CS:S (Only if you don't have CSS)

Update if anything helped 

Already downloaded
Come on...800+hrs I am not new player XD
I have tried Verify game files 
still thank for your reply

yeah I still remember you Apple : if you remember me :
if you need any help and you still didn't get it fixed pm me in discord @ Jumbo#1317