> The trailer is low so I'm also worried about a car passing behind me driving into it. I wonder if this concern is really valid. I have a Burley Bee trailer

> The trailer is low so I'm also worried about a car passing behind me driving into it. I wonder if this concern is really valid. I have a Burley Bee trailer and I've tested out approaching my bike with the trailer attached from behind both in my minivan and sedan vehicles and had no problem seeing the trailer. I've also noticed that vehicles tend to give me more space and are more conservative when passing when I'm riding with the trailer attached, so I don't think they have a problem seeing it. I don't bother using a flag though.