Ran into an interesting situation today (wish I had known this a week ago!).

Here in KC we have a Hertz location at the Westin Crown Center hotel. Right across the street from the Westin Crown Center is the Amtrak station (in Union Station). In the Hertz reservation system there is a location for the Westin and a separate location for the Amtrak station, but the Amtrak station location is really the Westin location ... the key difference being their rates are different!

What it looks like is the Amtrak station charges the same rates as the airport location, which can be very low on the weekends especially ... BUT, the add-on fees/taxes are much lower. As an example, just last weekend a rental from the airport that cost me $40 with taxes and everything cost cost me $30 with taxes and everything at the Amtrak location (which is actually more conveniently located for me).