I know a trauma surgeon fairly well. My grandfather was involved in a car accident/fire when I was in high school and she saved his life. Because of this, he volunteers down at the hospital where she works and I saw her quite a bit when the issue happened and still hear from her every now and again.
What I can tell you first-hand ...
God bless this woman (no joke, she's a hero), but she has the absolute worst work schedule I've ever seen. She essentially lives at the hospital, said she always wanted a husband and kids but never had time (she's not married), she physically had to live close to the hospital to get there quickly, works all the time, deals with horrendously complicated patients, etc, etc, etc.
I always hear people complain about certain rotations, residencies, etc, but I seriously don't know how much worse they can be than her work. Granted, she worked at a big hospital and didn't have to take care of the smaller stuff, but it seems like people who get into trauma are looking for the big thrill stuff anyway, so like Sideways said ... definitely research this continually (not just from the pre-med shadowing point of view) and keep in mind that you could change you mind.
Other than that ... my guess is that the trauma fellowships aren't overtly competitive. Although, it doesn't look like the AOA has any, which means you'll probably need to go ACGME, which means MD surg residency would be 'best' (even though for non competitive fellowships, AOA surg could work), and this could be a decent challenge TBH.