[Huawei Ideos X5 U8800] Parrad11:
I tried what you suggested to see if the volume level would change in Spirit, but it did not appear to adjust the volume, I could not try it on qdsp5v2 as the phone crashes after switching to that method and then turning on FM, so it was on the default CyanogenMod. (Tested on Aurora ICS)

Last bit of logcat output after trying to enable FM after switching to qdsp5v2

D/fm_srvc ( 1322): lengthy_pwr_on low_pwr_mode_set (false)
D/fm_srvc ( 1322): low_pwr_mode_set new: false old: true m_pwr_state: true hrdw_hndl: 6
D/fm_srvc ( 1322): dhrdw_pwr_set fd: 6 pwr: 17
D/fm_hrdw ( 1322): hrdw_so_pwr_set api_hndl: 6 pwr: 17 curr_pwr: 1
D/fm_hrdw ( 1322): gen_pwr_set: 17
D/fm_hrdw ( 1322): gen_pwr_set enable low power mode -> nothing
D/fm_hrdw ( 1322): hrdw_so_pwr_set curr_pwr: 1
D/fm_srvc ( 1322): dhrdw_sys_run fd: 6 cmd: /data/data/com.mikersmicros.fm/files/ssd 3 1 su: 1
D/fm_hrdw ( 1322): hrdw_so_sh_run api_hndl: 6 su: 1
D/fm_hrdw ( 1322): su_run: ' /data/data/com.mikersmicros.fm/files/ssd 3 1'
D/fm_hrdw ( 1322): sh_run: 'cd /data/data/com.mikersmicros.fm/files ; su -c "sh cmd"'
D/su ( 1455): 10075 /system/bin/mksh executing 0 sh cmd using shell /system/bin/sh : sh
D/memalloc( 108): /dev/pmem: Freeing buffer base:0x4215e000 size:286720 offset:4608000 fd:30
D/fm_hrdw ( 1322): hrdw_so_sh_run ret: 0
D/fm_srvc ( 1322): lengthy_pwr_on out_set / mute_set m_out: 3
D/fm_srvc ( 1322): out_set: 3 custom: false m_aud_meth: 8
D/fm_srvc ( 1322): audio_routing_disp getDeviceConnectionState: 0000 0000 0000 0111
D/fm_srvc ( 1322): dhrdw_mute_set fd: 6 mute: 1
D/fm_hrdw ( 1322): hrdw_so_mute_set api_hndl: 6 mute: 1
D/fm_hrdw ( 1322): v4_mute_set: 1
D/fm_srvc ( 1322): dhrdw_out_set fd: 6 out: 3 aud_meth: 8
D/fm_hrdw ( 1322): hrdw_so_out_set api_hndl: 6 out: 3
D/fm_hrdw ( 1322): qdsp5v2_out_set: 3
D/fm_hrdw ( 1322): su_run: 'chmod 666 /dev/msm_audio_dev_ctrl'
D/fm_hrdw ( 1322): sh_run: 'cd /data/data/com.mikersmicros.fm/files ; su -c "sh cmd"'
D/su ( 1460): 10075 /system/bin/mksh executing 0 sh cmd using shell /system/bin/sh : sh
D/fm_hrdw ( 1322): dev_id_get_disp sizeof (struct msm_snd_device_info): 72 num_dev: 21
D/fm_hrdw ( 1322): dev_id: 00 dev_cap: 0x00000005 dev_name: handset_rx
D/fm_hrdw ( 1322): dev_id: 01 dev_cap: 0x00000006 dev_name: handset_tx
D/fm_hrdw ( 1322): dev_id: 02 dev_cap: 0x00000005 dev_name: headset_stereo_rx
D/fm_hrdw ( 1322): dev_id: 03 dev_cap: 0x00000006 dev_name: headset_mono_tx
D/fm_hrdw ( 1322): dev_id: 04 dev_cap: 0x00000005 dev_name: bt_sco_rx
D/fm_hrdw ( 1322): dev_id: 05 dev_cap: 0x00000006 dev_name: bt_sco_tx
D/fm_hrdw ( 1322): dev_id: 06 dev_cap: 0x00000011 dev_name: fmradio_handset_rx FM Capability
D/fm_hrdw ( 1322): dev_id: 07 dev_cap: 0x00000005 dev_name: speaker_stereo_rx
D/fm_hrdw ( 1322): dev_id: 08 dev_cap: 0x00000011 dev_name: fmradio_speaker_rx FM Capability
D/fm_hrdw ( 1322): dev_id: 09 dev_cap: 0x00000011 dev_name: fmradio_headset_rx FM Capability
D/fm_hrdw ( 1322): dev_id: 10 dev_cap: 0x00000026 dev_name: tty_headset_mono_tx
D/fm_hrdw ( 1322): dev_id: 11 dev_cap: 0x00000025 dev_name: tty_headset_mono_rx
D/fm_hrdw ( 1322): dev_id: 12 dev_cap: 0x00000006 dev_name: speaker_mono_tx
D/fm_hrdw ( 1322): dev_id: 13 dev_cap: 0x00000002 dev_name: fmradio_stereo_tx
D/fm_hrdw ( 1322): dev_id: 14 dev_cap: 0x00000006 dev_name: handset_dual_mic_broadside_tx
D/fm_hrdw ( 1322): dev_id: 15 dev_cap: 0x00000006 dev_name: speaker_dual_mic_broadside_tx
D/fm_hrdw ( 1322): dev_id: 16 dev_cap: 0x00000006 dev_name: handset_secondary_mic_tx
D/fm_hrdw ( 1322): dev_id: 17 dev_cap: 0x00000005 dev_name: headset_stereo_speaker_stereo_rx
D/fm_hrdw ( 1322): dev_id: 18 dev_cap: 0x00000005 dev_name: speaker_music_rx
D/fm_hrdw ( 1322): dev_id: 19 dev_cap: 0x00000001 dev_name: hdmi_stereo_rx
D/fm_hrdw ( 1322): dev_id: 20 dev_cap: 0x00000005 dev_name: headset_music_stereo_rx
E/fm_hrdw ( 1322): dev_id_get_disp device not found: speaker_fmradio_rx
E/fm_hrdw ( 1322): m3_do A dev_id_get_disp error
D/fm_hrdw ( 1322): dev_id_get_disp sizeof (struct msm_snd_device_info): 72 num_dev: 21
D/fm_hrdw ( 1322): dev_id: 00 dev_cap: 0x00000005 dev_name: handset_rx
D/fm_hrdw ( 1322): dev_id: 01 dev_cap: 0x00000006 dev_name: handset_tx
D/fm_hrdw ( 1322): dev_id: 02 dev_cap: 0x00000005 dev_name: headset_stereo_rx
D/fm_hrdw ( 1322): dev_id: 03 dev_cap: 0x00000006 dev_name: headset_mono_tx
D/fm_hrdw ( 1322): dev_id: 04 dev_cap: 0x00000005 dev_name: bt_sco_rx
D/fm_hrdw ( 1322): dev_id: 05 dev_cap: 0x00000006 dev_name: bt_sco_tx

I tried the FM Transmitter from honking's FM Radio build, but could not get anything to transmit to another FM enabled device. It seems to find an internal antenna and will not allow you to plug in the headphones to create an antenna, unless to transmit audio over FM does not require the headphones.