[MrFlippant]

For that length of track, after the first lap or two, the cars will be REALLY spread out. Putting in more than a third lane that appears and disappears would just make it worse. IMHO, the point of digital is close racing. If you add lanes, you just reduce that. I'd only add a full third lane with more than 8 cars, and a fourth lane would need 12 or more, especially for such a long track.

That said, for some systems, it's hard to have more than two lanes. Some require some tweaking, some have the hardware needed off the shelf, and some are designed for as many lanes as you want. If you want to break the 6 car limit, your options are: Ninco (mm... wouldn't recommend it); Scorpius; or oXigen. DaVic is also an option, but is easily the most expensive of the bunch.

 

[MrFlippant]

It's generally true of any kind of racing where the car and/or drivers are not very closely matched.
I race with an analog home track club with guys who have been racing competitively for many years, and 4-wide is pretty rare. Once or twice a meet for a few laps, tops. Trying to film a lot of 4 wide racing, I've been surprised how rare it really is. Even if all the guys are on the same lap, it doesn't mean they're side by side. ;-)
I guess your guys are all very closely matched drivers and equally well tuned cars. That, or someone's holding back to stay in a pack. ;-)
I find that digital racing tends to have more close driving, if only because most cars tend toward the best line around the track, and many tracks are hard to make a clean pass on an equal driver having to get on the non-preferred lane. Then they eventually make it around to lap the back markers, and often have to run a few laps before a clean pass.
In either case, as soon as a car comes off, the field is spread out again, or if someone just overcooks a corner and then pulls back a bit in order to stay on better.

 

[MrFlippant]

I haven't raced all over the world, but I think 300SLR is lucky to have such regular close racing.
That, or our definitions of close racing are different.
If a car in the other lane(s) is more than a couple feet away, I don't call that close. If they're not even on the same turn, then forget about it.
Close is when someone is having to drive clean to avoid nerfing the guys next door, or hang back to avoid being nerfed, or in digital, to slow up and avoid rear ending.
If that's the kind of close he gets, on a regular basis, then I call that lucky. And I'm in an area with a plethora of slot racing going on all the time.

 

[MrFlippant]

Ah, that explains it.
Around here we race lane rotation and heats such that everyone runs every lane equally. There's no qualifying, and the rotation is randomized so you're not always racing along side the same people.
If we split people up according to skill (qualifying) like that, we'd have more close racing, too.