A rear subframe assembly, for use in a vehicle, includes a first and second side member that are coupled to a front cross member, a lower cross member, and an upper cross member. First and second gussets are provided to reinforce joints between each of the first and second side members and the front cross member. A motor mount portion for mounting a motor thereon is located between the side members and includes a first and second motor bracket each coupled to the front cross member through an isolator and to one of the side members through an isolator, the isolators for isolating the motor from vibration. A fuel tank mounting portion for mounting a fuel tank onto the subframe member is also provided.