I didn't see this written yet, so ... it's actually good that the negative terminal is hard to reach and encourages using a different ground location for boosting, because a ground away from the battery should *always* be used when connecting batteries that have been running (and charging) in a car. Batteries produce some Hydrogen gas while charging, and you usually make a little spark when you connect the ground (always done last) - i.e. ** you do not want that spark near a battery that could be emitting exposive gas! **
This is also why it's best to connect the "dead" battery last when giving or getting a boost.