It's part of the problem, but I don't think we've studied individual contributors as much as looked at the big picture. There was a recent study on plastics in general that has some citations of the statistics it gathers, and I ran across it in looking up specifically the rubber from tires, aka tire dust from wear and tear (which all vehicles have to some degree, even EVs, and is often a part of the argument of less cars rather than different cars). So about 1 millions tons of the annual contribution to plastics in the ocean is due to tire dust in runoff waters. Also keep in mind that like many large studies that take a while to put together, I think a lot of these statistics are old (around 2016). It's probably worse now.
Two more variables that are going to affect the number of encounters are when the "final" orbits of the inner planets were established (the Nice model suggests there was much disruption early on) and that Mars' orbit is very elliptic so it's rarely lining up at its closest approach, which is still pretty far. If anything we'd more likely see some correlation between Earth and Venus if there is any.