Rearview Mirror problems of the 1999 Acura RL

The rear view mirror in my wife's 1999 Acura Rl has a liquid substance sloshing around inside. My wife was complaining of a headache that day when she came in, and, not knowing the contents of the mirror, I removed it for fear that it would leak. The dealership quotes $300+ to replace, which I feel is unreasonable for the type of part we're talking about. I located other consumers who had the same problem, except that they left their mirror in place and it either leaked or exploded. Apparently the liquid inside the mirror is corrosive because in every case the interior of the car was ruined wherever the substance came in contact with it. I then contacted the manufacturer of the mirror but they have so far ignored my calls and emails.