Yes I noticed the same, I had always thought that my hometown had very clean air (which by comparison it has) and that's why I never could smell pollution. After some staying at home during the pandemic, even the clean modern cars that passed every ten minutes or so on the calm suburb road REEKED of burning hydrocarbons. Going near the main road was terrible. Now again I can't smell the cars, the main road feels like clean fresh air (even though there are way more cars) maybe if a small motorbike drives by I can smell it