My advisors (first two authors of a major surgery text) suggested a very different strategy:
First, do a SICU month and brush up on physiology and patient management.
Then, do a home surgery elective AI (like burns or trauma with someone well known at your school who will write a letter). Read up on cases ahead of time, be early, stay late, be available and affable = great LOR.
They dont expect you to be much better than 3rd years, but you should be more efficient and probably will understand the medicine behind the diseases better than the newbies.
Also, you can look really good by doing some teaching - show the third years the ropes a little, it makes you look like a good team player.
Then do at least one away AI at another program with big name faculty where you might want to go for residency. Set up a meeting in advance with the faculty of interest, and let him/her know you are a visiting AI and will as them for a LOR at the end of the month. Try hard to work with their team and scrub in with them when possible. Volunteer (!) to take extra call with various residents on the faculty's team, and also on nights when that faculty is on service. This will get your name out there in the 4 weeks you're there.
Later in the year, do an easy radiology elective. Between SICU, radiology, trauma/burn and a general elective you will have plenty of surgery to make you a good candidate for internship. The rest of 4th year, do whatever the hell you want, the minimum to graduate if that suits you.