Welcome to CPF Ripples. My experience with spotlights is limited, but I'll pass on what I've learned here. I took member recommendations and purchased a Stanley HID spotlight and I've never regretted it. The Stanley has a pistol grip so it should be easy for you to manuver and point as you steer.
I'm not going to lie to you and say it will light up a loading ramp from a half mile away, but the Stanley HID is ridiculously bright. For the price I just don't see how you can beat it. The good news is you should be able to locate one at your local Wallyworld. Check the package identification as your looking for a Stanley HID 3000. You'll probably notice other model's that are cheaper, but I'm not recommending anything but the HID 3000.
Now, for the bad news. It's a little over your budget of $50. Most of the stores in my area have it at about $70. If you can swing that you won't regret the purchase IMHO. Oh, check the package to make sure it comes with a 12V DC cig. lighter plug in. You'll need that in addition to the AC charger that comes with it. My unit came with the DC charger plugin, but I've seen some web sites that sell the Stanley HID and don't mention the DC cord being included.