Hello I am new recently acquired a 2004 S60 turbo. Only has 1 key. I understand must have FOB to start car and would like info on that but would like extra door key as back up to get in car. Thank you, Ron.
Welcome to the Forum.
The "best" way to get a new replacement key/fob for your 2004 S60 is to call an authorized Volvo car dealer as the fob will need to be programed to operate all your car's remote functions.
Yes, you can buy a fob/key online but you will need the Volvo VIDA download ($$) plus the code on the fob/key and lots of luck to make everything work.
If you want to try this on your own holler up and I'll link you to the correct part number and source.
Thanks.
George Dill