My tuner module gets excellent FM reception, quite comparable to most aftermarket tuners (although I don't have one of the super-fancy new Sony tuners to compare it to so I don't know how it stands up to those).

So if you're getting really bad reception with the tuner module, as bad as you're describing, then something is wrong. Most likely a wiring problem, or an improperly connected antenna amplifier, as described in the FAQ. However, if you've ruled out those problems, then you should contact support because a defective tuner unit is not completely out of the question.