It's actually still available, and it works with Win 10 with no extra hassle required. It lacks some of the technical features most games have these days*, but it works just like back in the day.
^(*things like windowed mode or ~~gamepad support~~)
^(Edit: it does support gamepads)
Ignition on PC was awesome fun. The track selection was a bit limited (5 tracks plus 2 more unlockable), but the quality of the tracks and the gameplay more than made up for it. And it ran fantastic on a Voodoo card.
Also, GeneRally is a fantastic racer with a HUGE community, first released way back in 2002 and it is still popular. There are custom tracks galore for this game. Much along the same lines as Super Off Road with a fixed camera angle and the whole track on screen.
Got with a bundle... is good fun. Also looking at Real World Racing... same concept (top down racer), but on real world street maps. And the PC classic Gene-Rally is coming back with Gene-Rally 2, very excited for that... will likely jump on it's KickStarter when launched.
You have to at least give Gene Rally a try:
It's a really fun top down racing game, with tons of tracks and lots of different car types. Make sure to turn down the AI cars skill levels a bit right off the bat, because they come set waaay too high, but if you get them low enough the game is very accessible with bright shiny colors and fun sounds.
Plus, it's free, and the community is constantly making new tracks and new cars for it.
GeneRally, a top-down arcade racing game that comes with a track editor.
Lots of tracks and cars made by the community are available, and some tracks are still second to none in layout and design.
Also, pit stops in this racing game are super fun!
Is this your game?
Anyway, I love this in principle -- like Gene-Rally for the web. Gene-Rally had much more satisfying handling though, hopefully this can be improved. It either feels like driving on oily ice or on rails, depending on the car.
Edit: to add a few positive things, the graphics are very clean, having an AI is fantastic for multiplayer games just starting out, interface is clear.
Edit2: I think you should set the Trident as default car, easiest to handle IMO.
Edit3: Like the track editor - took me a few minutes to get used to it, but very easy to customize a track.
GeneRally. Free, and runs great even on low end hardware. Decently fun, especially with a friend (no split screen - you're both looking at the same screen, controlling your own cars). Has quite a lot of content available on the internet - tracks, cars, color palettes, sound packs etc, and you can also make your own.
Actually reminds me of a small old game me and some friends used to play called Generally. It's free to download at their website.
>realistic racing games with robust track editors
There are only a few racing games that have track editors at all. Can't think of any realistic ones that have robust editors.
All the Trackmania titles, Gene-rally... and if you include RNG editors, there's also Gran Turismo 5 (haven't played 6) and V-Rally 2 (yeah, i know...).
Those are all i can think of right now. Oh, and you can set up a race in GTA Online, i suppose.