Although I do not own a volvo (see my post about the Volvo I am loooking at), I have driven many other cars. The red light on the dash is most likely the security system. Most factory security systems are activated when the all the doors are closed and the car is locked using a key or the keyless fob. However, if the light flashing is on the radio, that is the radio's anti-theft feature. If this feature is activated, watch out. The last owner probably activated it and used their own code to use it. If the batery is disconnected and then reconnected, the code will be needed to use the stereo. If you do not know the code to unlock it, then you will have to go to the dealer who may charge you to unlock the radio. Sorry to digress but thought you should know.