I don't plan to replace all of traffic, as if I did that I think my computer would just implode on itself on the spot, probably creating a black hole along with it, but I can't seem to find a list of vanilla traffic cars. Anyone got any idea where I can find one so I can replace a few cars from the list to see some real cars in traffic? If this has been asked already sorry about that, I'm brand new to the forums. Thanks!
I don't think you'll have much luck finding an accurate list like that. I've never seen a valid or thorough one anyway. Not very many replace vehicles actually replace their in-game counterparts either.
If you want to find replacements for a specific vehicle, best bet is to use a Google Site Search (can be edited to different sites/searches etc) to hunt for likely candidates.
Generally tho, a lot of mod authors only put the name of the vanilla vehicle in the download's 'Read me' etc, so there will always be a little bit of downloading & checking involved.
Whatever you do, avoid big youtube car replace packs, they very rarely, if ever, come without issues.
Ideally, you want to install vehicles one at a time (or in small numbers anyway), so you can test them thoroughly for stability, before continuing to mod/add more etc.
Use Add-On as Replace:
Also, just so you know, add-on vehicles can be spawned ambiently on the streets/in place of vanilla vehicles as well, you don't always have to use a replace. More info on that process in this post.
Every time I've tried to use add-on traffic my game always has a problem with something and crashes, and I haven't been able to figure it out. I tried early last year when I was starting out modding and I tried it last month with no more luck than the last time. That's why I wanted to try this route.
You'll want to have a read over this thread, it covers a lot of 'good practice' concerning replacing vehicles.
Also, ideally, you want to try & find as many vehicles that have LODS as possible & use them instead of vehicles with no LODS. That will reduce some of the performance hit/instability associated with modding traffic.
For the replace vehicles you have that have no LODS, you probably want to reduce the number of them that can spawn at the same time.
More info on that, & some other stuff, here.