IronHorse Amateur Radio Mobile antennas were easy to tune, relatively inexpensive, and performs very well. My first HF contact with the IronHorse 20M stick was with another mobile in Minnesota. As a bonus, the antenna is easily disassembled by unscrewing the stainless steel whip assembly, turn around and slide the stainless steel whip into the fiberglass body for easy storage.
Note: The set screws will rust. It is recommended that they be replaced with stainless steel set screws. My local Home Depot and Lowes do not carry the set screws for this antenna, but True Value Hardware does. They are Metric, size M4 x 5 (0.70 pitch). M4 x 6 will also work in most cases.
The following are the results I have seen on my vehicle (not using a tuner). For 40 and 75 meters, I am using the LDG RT-11 automatic tuner, which works well with these antennas
The IronHorse HF Antennas were easy to tune, bandwidth always wider than specified. Stations from coast to coast as well as south American and European stations were easily heard. This line of antennas are recommended.