If I had left an salad in my car with an boiled egg in it for a whole day and night, will it still be OK to eat the next day for dinner?

I would say NO!! But I guess it would depend on how cool it was during the day and night... But it's not usually a good thing to eat egg OR lettuce that has been sitting out.

If your talking 'egg salad' with mayo, don't go any where near it without rubber gloves.:eek: