I went with two 470 uF's in series, making a non-polarized cap out of two polarized caps. This gives me a 235 uF cap.

I don't like it - took TOO MUCH bass out, IMO.

But I did something else, I only did ONE speaker, the driver's side. Gonna drive around and play with it (using the balance control to switch sides and compare) for a few days.

I THINK about a 330uF or so might be about right - I agree that there is too much bass as the factory set it up, but the 235uF I have in there is too little, and takes TOO much out.