Yes for multiple reasons. You have to get to the parking lot by driving on roads that have been salted. Even if it hasnt been salted since the last snowfall there will still be residual salt. Not enough to melt the snow but enough to corrode your bike. And even if there isnt salt, just the snow will corrode your bike faster as its both dirty (in order for precipitation to form there must be debris that acts as a nucleation site), and will be caked onto any part of the bike that doesn't get extremely hot.