It's pretty bad, actually. Assuming you'll be using it to split off an antenna mounted on the right fender, it's very directional and you'll find the sensitivity reduction on the railroad band is significant compared to a dedicated antenna. If you were listening to strong repeater frequencies it might be OK but you need evey extra millivolt with railroads. I'd look at a 1/4 wave whip with a mag mount if you don't want to drill a hole in the top of the vehicle or a Diamond 5/8 wave gain antenna with a trunk lip mount before I'd use a splitter.