Tundra is big as well, even if most of the track is wide, just 20 or 30 off kilometers of narrow track can ruin the whole race, remember i lost Evo's tyre in rocky portion of Jhal, was doing 135-140 on a twisty rocky portion with probably only a few inches on both sides, one has to do it to compete the forerunners. A normal person would not dare to be higher than 40 km/h there but that what one is expected to do in rally.
If someone is putting in 5M or more, plus the preparation cost of atleast 1.5M, he is aspiring to be pushing the existing table, which he would not be able to do on such wide vehicles.