Just remember it needs to be close to a window. It doesn't work for example in the middle seat of a car or pickup.

I f you're planning to use the handheld on some longer trips, make sure you get one with more than 8Mb of extra storage. I can only upload enough higher precision maps for about a 3 hour road trip. Cities will take up a lot of memory. 

 I used my handheld this summer on my sprayer. Its real easy to measure the field size by just driving around it. It wont be right down to the last acre but very close. It also keeps a pretty precise speed measurement. Pretty much identical to my radar speed sensor. Very cheap speed monitor and area calculator. Yo might want to pick up a 12V car adapter as the batteries drain pretty quick.