Decals are from brandsoftheworld, the web or even handmade in some cases. Been collecting logos for a couple of years. Not keen on giving them away, but take a look at the d1rdgp mod (www.fsr.no/d1rdgp). I've released templates for all the cars, and you can find a lot of logos there. Just remember to credit me if you use them in public skins...
And I'll give away a secret: A good way to find eps logos is to try and find pdf cataloges from the company you want the logo from. Very often they contain a vector version of the logo
No one knows for sure. A couple of years ago it was a huge trend in Japan to have the right side mirrored. Not all logos, but the ones that were a part of the design. I'm guessing there are several reasons:
1. Better symmetry in the design...
2. Most italic text and logos lean to the right, making them lean against the direction of travel on the right side of the car...
3. The Japansese don't usually use our greek letters, so they just don't care what way it is as long as it looks pretty...
4. You will see the design the correct way when cruising past a big store window...
4. It's easier to make...
Some explain it as jin jang, saying that the design needs to be symmetric due to eastern culture. Not so sure though, as Japanese race cars usually have the logos the right way...
So if we break it down we see that it's a trend limited to japanese drifting/street racing. That kind of supports the theory that street racers want to se their design while cruising in the city and enjoying the reflection in windows.
I think it's a combination of that, and the fact that it's way easier to make it look good. And of course it does work in order to draw attention. Not anymore perhaps, but the first dude who did it probably got a lot of attention. So everyone else just followed, making it a trend. Not really having a reason at all...