Resins and bondo are very bad for your lungs and your nervous system. If you can smell it, you're in trouble.
A good organic vapor respirator will do what you need, they're like 30$, and are obvious because they have the large triangular or circular canisters on the "cheeks". The cartridges give you a lot of use before they need replacing, and it's a good thing to have in any toolbox.
There are a lot of people who brush off the risk, but it's a very real danger, and while really light exposure like a brief whiff will at worst cause some irritation, a deep lungful can cause you troubles, and it's just not worth risking it by saying "I'm outside, the wind will carry it away", because it just takes one change in the winds to blast it in your face. I am a bit preachy, but I think being aware of the risks is important, especially with so many younger members here.