Zarp Pack, not sure if that's still a thing but it's an addon on the steam workshop that includes most ad dons you need. Just type Zarp pack in the work shop. Another add on would be TDM, the cars used on the server which is pretty famous in Garry's mod. Make sure to google TDM pack or something close and a link to all the tdm car adding you need should appear. Next, you look for the subscribe to all button found on the first page a bit under the top of he page of I'm not mistaken.
Good luck! Sorry for grammar and spelling mistakes, I'm on my phone.