Something

modules=( "dhcp" "wpa_supplicant" )

# Configuration of your wired stuff (might differ a lot)
config_eth0=( "dhcp" )
dhcpcd_eth0="-t 10"

# ath0
config_ath0=( "dhcp" )
dhcpcd_ath0="-t 30"
wpa_supplicant_ath0="-Dmadwifi"
wpa_timeout_ath0=60
essid_ath0="CrapWap"

# Prefer wpa_supplicant over wireless-tools
modules=( "wpa_supplicant" )

# It's important that we tell wpa_supplicant which driver we should
# be using as it's not very good at guessing yet
wpa_supplicant_ath0="-Dmadwifi"