Not too many people have been buried sitting on wagons. The most famous case is that of an Early Bronze Age man who, considering his injuries, may have died in a high-speed crash - high-speed for its time anyway - on the Pontic-Caspian steppe in Eastern Europe.
It's likely that this guy was one of the very first wagon-drivers in human history, because his four-wheeled wooden model is dated to 3336-3105 calBCE, which makes it the oldest wagon discovered thus far. His genotype data, under the label Steppe Maykop SA6004, were published recently along with
Wang et al. 2019.
Early wagons are very important for a couple of reasons: they revolutionized human transport and warfare, and they're often closely associated with the prehistoric expansions of Indo-European languages.
So I'm pretty sure that many of you must be thinking right now that wagon-driver SA6004 was an early Indo-European, or even a Proto-Indo-European! I bet that's what Wang et al. thought too, considering the conclusion in their paper. But, alas, the chances of this are slim to none.
Steppe Maykop samples show rather peculiar genetic structure considering their geographic origin, with a large proportion of their ancestry deriving from a source closely related to western Siberian hunter-gatherers (aka West_Siberia_N in the ancient DNA record). Indeed, SA6004 basically looks like a 50/50 mix between West_Siberia_N and Piedmont_Eneolithic. Here's a map with all of the relevant details.

Thus, clearly, the Steppe Maykop population wasn't ancestral or even directly related to the steppe and steppe-derived groups generally regarded to have been Indo-European speaking, such as those associated with the Yamnaya, Corded Ware, and Bell Beaker cultures. That's because these groups lack any discernible West_Siberia_N-related ancestry.
It also wasn't ancestral or directly related to any present-day or currently sampled ancient Indo-European speaking populations, again because these populations basically lack West_Siberia_N-related ancestry.
On the other hand, Yamnaya, Corded Ware and other closely related groups show an exceptionally strong genetic relationship with Indo-European speakers, especially those from across Northern Europe, which experienced massive migrations from the Pontic-Caspian steppe during the late Neolithic period, and hardly anything from elsewhere since then.
Case in point, the samples from Wang et al. labeled Yamnaya Caucasus were recovered from the same area of the Pontic-Caspian as their Steppe Maykop samples, and yet, take a look at this linear model based on outgroup f3-statistics. Steppe Maykop does show high genetic affinity to Indo-European speakers (no doubt mediated via its Piedmont_Eneolithic-related ancestry), but, unlike Yamnaya Caucasus, it also shows unusually high affinity for a West Eurasian population to Native Americans and Siberians. The relevant datasheet is available
here.
So the only way that the Steppe Maykop population was Indo-European-speaking, was if it inherited its Indo-European speech from its Piedmont_Eneolithic-related ancestors. And even if it was Indo-European-speaking, it probably spoke an extinct Indo-European language not closely related to any extant Indo-European languages. In other words, the possibility that Steppe Maykop passed on its language to Yamnaya, along with its wagons, is close to zero. More likely, Yamnaya stole a few wagons from Steppe Maykop, and the rest is history.
See also...
The Steppe Maykop enigma
On Maykop ancestry in Yamnaya
Late PIE ground zero now obvious; location of PIE homeland still uncertain, but...