oki am new here and this is what you need to build.
1-first build a digital 10-30second voice recorder(there are all in one kits you can buy for cheap which includes a bread board and components.)
2-record the sound and it will be stored on the chip.
3- use the speaker output of recorder and connect a 4ohm speaker to it that small.
4-the smd play button on the recorder solder wires on it,when it closes or pressed the circuit is closed and sends the sound out.
5-Now use relay and wire it up so the interior light wire of the car door switch sends a negative to relay coil to energise.... the the NC (normally closed to NO(normally open pins.(relay diagram google is your friend)Switch the relay on when the door opens.
6- now use the relay to close the switch on the board(the digital recorder play button) and viola you have any sound playing when opening the door.
Ok this is long way.
There are easier ways to do this is with another type of circuit but to be fair this one is really simple for moduler expansion to greater things.
let me know when you need any further help.
edit:if you require different sounds for other things in your car then use the 8 channel digital recorder,and also this means you gonna need to solder on all 8 switches to be closed for each 8 sounds...phew thats lots of wires but it can be done.I did it making a customer car talk to him with his voice for door open ,door closed,ignition off,starting,battery low,temperature hi..etc
But this was done with other circuits all coming together as one.Good luck and enjoy