My story won't include car-shopping -- at least not for anything like a 2004 Jetta wagon. But when my son-in-law inspected the spare tire compartment, I remembered a telling, tiny detail.
The Jetta's previous owner lived where all the roads aren't paved. While the detailers had cleaned and polished the rest, they'd neglected the spare tire bay. All around the tire, and inside some hidden storage compartments, we found a layer of fine, tan dust.
Suddenly I remembered my years of driving unpaved roads to work – the billowing clouds that followed me and the fine layers of silt that worked its way into every crevice.
It's something my protagonist, a jazz musician in 1925 Indiana, would regularly experience. That's where things get tricky. To my character, it's a normal detail of life. But it's also a subtle way to give readers a sense of that era.
Likewise the smell of coal smoke, the hiss of steam, and the fine black grit that blows into the open windows of coaches behind a locomotive. Start the trip with a white shirt and by the end of the day it's gray, with darker deposits around the cuffs and collar. Good thing those celluloid Arrow collars detach.
At my upcoming visits to antique car museums, I plan to pay special attention and take lots of photos of pre-1925 models. I know only a few of those details will make their way into the story. But at this point, I can't know which.
I want to include enough grit for my story to ring true.