[Android Head-Units] KoTiX2:
You can assign different functions to each buttons editing adset.xml and choosing from this list:

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Old_Rem_open 20
Old_Rem_angle_dec 87
Old_Rem_angle_add 65
Old_Rem_src 70
Old_Rem_eject 9
Old_Rem_fr 29
Old_Rem_ff 31
Old_Rem_dvd 13
Old_Rem_play 25
Old_Rem_next 17
Old_Rem_prev 27
Old_Rem_navi 21
Old_Rem_goto 23
Old_Rem_disp 18
Old_Rem_menu 89
Old_Rem_band 8
Old_Rem_sound_add 80
Old_Rem_menu_up 72
Old_Rem_mute 94
Old_Rem_menu_left 6
Old_Rem_enter 5
Old_Rem_menu_right 3
Old_Rem_sound_dec 71
Old_Rem_menu_down 64
Old_Rem_mode 24
Old_Rem_1 68
Old_Rem_2 15
Old_Rem_3 81
Old_Rem_4 30
Old_Rem_5 14
Old_Rem_6 26
Old_Rem_7 82
Old_Rem_8 1
Old_Rem_9 69
Old_Rem_10 10
Old_Rem_0 83
Old_Rem_eq 85
Old_Rem_cap 74
Old_Rem_aud 7
Old_Soft_Rem_BT_Call 231
Old_Soft_Rem_BT2_Call 65
Old_Soft_Rem_BT_Recall 233
Old_Rem_test_poweron 234
Old_Rem_test_poweroff 237
Rem_volume_add 76
Rem_volume_dec 77
Rem_pow 75
Rem_KEY_pow 214
Rem_angle_dec 74
Rem_angle_add 73
Rem_open 72
Rem_nightmode 71
Rem_videomode 70
Rem_pip 69
Rem_eq 68
Rem_dvd 67
Rem_menu_up 66
Rem_src 65
Rem_menu_left 31
Rem_enter 30
Rem_menu_right 64
Rem_navi 27
Rem_menu_down 29
Rem_band 28
Rem_call_receive 26
Rem_menu 25
Rem_call_reject 24
Rem_eject 23
Rem_play 22
Rem_stop 21
Rem_disp 20
Rem_prev 19
Rem_ff 18
Rem_fr 17
Rem_next 16
Rem_setup 15
Rem_sound_dec 14
Rem_sound_add 13
Rem_mute 12
Rem_1 11
Rem_2 10
Rem_3 9
Rem_4 8
Rem_5 7
Rem_6 6
Rem_7 5
Rem_8 4
Rem_9 3
Rem_10 1
Rem_0 2
Rem_other 0
Rem_enter_GOD 32
Rem_digi_red 96
Rem_digi_green 97
Rem_digi_blue 98
Rem_digi_yellow 99
Rem_digi_epg 100
Rem_digi_key 101
Rem_digi_recall 102
Rem_digi_fav 103
Rem_digi_ttx 104
Rem_digi_menu 105
Rem_digi_info 106
Rem_digi_exit 107
Radio_Rem_prev 108
Radio_Rem_next 109
vdisc_Rem_nor 112
vdisc_Rem_fast 113
vdisc_Rem_delete 114
vdisc_Rem_copyexit 115
vdisc_Rem_disc1 116
vdisc_Rem_disc2 117
vdisc_Rem_disc3 118
vdisc_Rem_disc4 119
vdisc_Rem_disc5 120
vdisc_Rem_disc6 121
vdisc_Rem_disc7 122
vdisc_Rem_disc8 123
vdisc_Rem_disc9 124
vdisc_Rem_disc10 125
vdisc_Rem_disc11 126
vdisc_Rem_disc12 127
vdisc_Rem_disc13 128
vdisc_Rem_disc14 129
vdisc_Rem_disc15 130
vdisc_Rem_disc16 131
vdisc_Rem_disc17 132
vdisc_Rem_disc18 133
vdisc_Rem_disc19 134
vdisc_Rem_disc20 135
Rem_dvd_AB 138
Rem_dvd_zoom 139
Rem_dvd_angle 140
Rem_dvd_goto 141
Rem_usb 145
Rem_dvd_display 146
Rem_dvd_title 147
Rem_dvd_pbc 148
Rem_dvd_capture 149
Rem_dvd_return 150
Rem_dvd_audio 151
Rem_dvd_sub_t 152
Rem_dvd_Last_Memory 153
Rem_cd_save 154
Rem_dvd_repeat 155
Rem_dvd_random 156
Rem_AST_scan 158
Rem_scan 159
Soft_KEY_COLOR 154
soft_Rem_mode 155
Soft_Rem_cap 156
Soft_Rem_aud 157
Soft_Rem_aux 212
Soft_KEY_sound 159
Soft_GPS_POS 160
Soft_GPS_DES 161
Soft_GPS_ZOOMADD 162
Soft_GPS_ZOOMDEC 163
Soft_Rem_vcdc 164
Soft_KEY_tv 165
Soft_opel_BC 166
Soft_opel_OK 167
Soft_opel_LEFT 168
Soft_opel_RIGHT 169
Soft_opel_SET 170
Soft_opel_setexit 171
Soft_Rem_fm 172
Soft_Rem_am 173
Soft_opel_N1 176
Soft_opel_N2 177
Soft_opel_N3 178
Soft_opel_N4 179
Soft_opel_N5 180
Soft_opel_N6 181
Soft_opel_N7 182
Soft_opel_N8 183
Soft_opel_N9 184
Soft_Rem_cam 185
Soft_Rem_prodo_receive 202
cruze_Rem_config 203
cruze_Rem_time 203
cruze_Rem_back 204
Rem_steer_src 205
cruze_Rem_prev 206
cruze_Rem_next 207
Soft_Rem_left 215
Soft_Rem_right 216
Soft_Rem_enter 217
Rem_android_home 229
Rem_android_menu 230
Rem_android_back 231
Rem_null 255