1) the trunk light turns itself off after 90 secs. (at least mine does) 2) I doubt the trunk is tight enough that a thin cord would damage the seal, but that is something to look at.
I guess I should have just read the batteryminder instructions. Apparently you connect the + cable to the battery and the - cable to the chassis, so the front posts would probably work. However, It also says not the charge the battery in a confined space, so the trunk may need to be open anyways. ETA: This was never a problem on the boat since the batteries are not confined and not grounded to the fiberglass. lol