[strat61caster]

Personally I do not believe it is wind, I had an old boxy '80s truck that was absolutely affected by wind and you could hear and feel when a gust caused the car to move. The 86 is absolutely less affected by crosswinds and large commercial vehicles due to it's low profile. There are some here that believe it is wind, I regularly drove across a bridge that routinely gets flagged with 'high wind advisory' 30+ mph gusts easily on a good day, the 86 is very easy to maintain in lane provided the alignment specs are conservative.

IMO it is wheel alignment and road related, ask for an alignment to be performed on the car, a little toe in all around will likely have it feel just like you want it to, factory alignment specs are not perfect, and maybe the dealership set alignment to be a bit more aggressive during pre-sale inspection since that's what many 86 buyers like.