Tom Tom through car speakers

Hello all I have just got my Tom Tom go920 and want to use my car speakers, I live in Spain and dont seem to be able to tune Tom Tom in anyone know what I could try ???

Think you need Change Preferences-->Speaker Preferences.

How do I do that
Please

As DHN states, you need to do the following:
1) Find an FM radio station on your car radio that has nothing but static (i.e. maybe 102.3 FM)
2) Tune your radio to the 102.3 frequency
3) On your TomTom GO:
a) Select the CHANGE PREFERENCES icon
b) Then select SPEAKER PREFERENCES
c) Then select the speaker you want your GO to use for announcing instructions (if you want the instructions to come over your car radio, select FM TO YOUR CAR RADIO)
d) Then select the speaker you want your GO to use for playing music (if you want your MP3s to play over your car radio, select FM TO YOUR CAR RADIO)
e) On the next screen, click on CHANGE
f) Input the exact same digital frequency from Step 1 above)
g) Click OK
h) Then Click DONE

Everything should be all setup now

Here's my low-tech method since the radio option doesn't work in my car (I guess the antenna is too far away): insert one of those tape player adapters with the cord hanging off of it into your car's tape deck. Insert wire into TomTom. Press play on the tape deck. By default all music and instructions will play through the car's speakers. No settings to modify.

Yet another good option!