The parking sensors (front & rear) on my 2006 S Type XS series is very faint, any suggestions as how to increase volume most welcome

I know on my Chrysler 300 you can get louder upgrade from main dealer, might be an idea to give them a call.

I would add that the jaguar to me sounds loud, but wife cant hear them, yet on the Chrysler I could not hear them but she could, it maybe  case of the different frequencies than the loudness.

Having said that, don't know where the sounder is located on the S-type (other members can help with location) they might be obstructed or even taped over my the PO. if its anything like the Chrysler they use a small piezo sounder and in my case it was cheaper to buy a new (louder buzzer) and just soldering it in after removing the old unit,

there is normally a manufactures part number or code, if you can get that then you can look up the specs, you need to know the voltage and the sound level, the voltage is critical, the sound level is a matter of choice, Maplin electronics store may even let you hook up to a battery, or just but s couple of different values from ebay (make sure the voltage is correct) they are under £5 each..

Just looked in the manual and the front sounder is in the instrument cluster, the rear unit seems to be a stand alone unit.

 

Just found the information on the front sounder  Digisound F/BMS3408-01 it appears to be a small speaker/sounder easily accessible once you have unclicked the instrument rear clusted.

 

Hope this helps