XC90 access interior roof bulbs? Headliner? -- Relates to iPod - not a joke

I couldn't find an iPod solution for my XC90, so I tried an experiment.
I got about 15 feet of very thin insulated wire. At one end I wound a
little coil and taped it on the OUTSIDE to the plastic roof pad where
the antenna hides. I then snaked the wire through the right passenger
door, tucked it under some trim, and ran it up to the front console. At
the console end of the wire I wound another little coil and taped it to
the bottom of the shelf in the console (on top of that little rubber
mat). When I sit my Ipod (with Itrip FM modulator) on that coil, my
Ipod sounds great thru my radio. Well...maybe not great, but as good as
an FM modulator can sound, with no hash or static. Before the hack with
the wire, I only got garbage. BTW, this is in the SF Bay area, where
everyone complains about FM modulators due to the density of FM
stations.

What I have now finally works, but it's a kludge and I want to "clean
it up". I'm hoping there is access to the FM antenna compartment from
the inside (Volvo wired it somehow). All I would need to do is poke a
wire up through a hole in the roof into the antenna chamber (if I can
find the hole) and snake it under the head liner. Does anyone know how
I might do this? I thought I might get a better look by pulling the
ceiling lights in the back, but they don't want to budge and I don't
want to break anything.

If I find a clean way to do this I'll post pictures. This really works,
does not interfere or connect to any part of the car, and no soldering
is needed

 

They sell kits that run from the FM modulator, to where the car antenna
connects, at the back of the radio you know... FM radio antenna connections
are suppose to be standard... looks kinda like an RCA jack.

 

Posts on Swede speed and elsewhere say that this will not work on the
XC90 do to the weird MOST fiber optic system. From what I've read, an
in-line FM modulator can't be used. I know this is strange, but it
looks as if the connection from the antenna pod up to the radio may be
optical and not be RF. I don't want to rip up the car too much, or risk
damaging the sound system (I have an 8 year extended warrantee). What I
propose is non-invasive and my taped-up job works very well. I was
hoping someone had worked in the headliner area and could give me some
tips, but it appears not.