It is all a bit of a headache as their are many factors and this gets a bit technical.
Using EQ is a bit of an issue too as it can require PRE OUTS from a 5.1 Amplifer going to seperate amplification with the EQUALISER in between for L/R audio control to alter your wind noise etc.
Factors:
Various games outputs differ.
Various viewpoints in games differ in audio strength of effects
Various amplifers will have differences in LFE control and output
Various amplifers have differing DSP and surround modes which effect LFE
Various Buttkicker devices will have differing performances
Various additional equipment and amplification needed to have more control
Leave out the EQ for now and concentrate on beefing your mid-low range audio. This way you can have it in a sense louder or balanced to drown out the wind noise.
If a kerb in a game doesnt make much low end bass noise (as some dont) then yes a Buttkicker will get little effect via the LFE. I understand your problem here. However normal speakers as you comment have a decent audible bass sound from them. So you can indeed cover both options as I have previously tested. One way is as mentioned is using good audible bass in car audio subwoofers to enchance the bass as a sub speaker has a much wider range than a Buttkicker. I think this would instantly help your issue when increasing volume to benifit the LFE the wind noise becomes unbarable. Trust me add at least one 12" sub with a 4ohm amplifer and it will be a big benifit when used with a Buttkicker.
Another trick is to to take audio from the centre channel or left/right. Using a 2nd 5.1 decoding amplifer or even stereo amplifer with optical input. You can do this combined with the PS3 multi audio output. Turn it on in system menus.
Now you could have 2x 5.1 amplifers, 1x HDMI 1x Optical.
"System A" doing the normal speaker thing and a LFE going to a Buttkicker(s) and subwoofer(s). You may also have Sub Harmonic in between the LFE output and Buttkicker(s) and if like me a seperate one for subwoofer(s) for individual control of each as mentioned above for more enchancement or control.
"System B"
Using normal game audio output of L/R or Centre channel to either a Buttkicker or subwoofer for bass enchancement. Just like a stereo system with a sub in between the speakers. This will give a good beefing of general game audio bass not the LFE effects.
I think though a Clarke Tactile unit will act better here than a Buttkicker with their more varied performance although as recently only got mine I will have to test this.
Just some of the components Im using with my journey and experimentation...