Prior to taking off to a ski trip in Montana and some hiking in the Coos bay area of Oregon, I added a toy and some, lights to my 610.
The toy was an XM satellite radio. This is way cool, 170 plus stations of any kind of music sportsl, news, and weather. I also took out the Delco cassett deck and replaced with an am/fm cd player that I could hook the XM receiver up to directly. I got the Sony XM which has a unit that I can bring into the 5th wheel with me and receive sat radio there as well. Great addition.
The second add was additoinal driving lights. I have not be overly impressed with the standard Volvo headlights, they have very little light out to the side making direction signs difficult to pick up. I lurk on the MAK bus conversion site, and they have had several discussions about head lamp replacement etc.
I called the US distributor for Cibie headlights and asked for his recomendations. Instead of adding fog lamps and driving lights I added another set of high/low beam e-spec head lamps. These are the "Oscar H4 chrome v-Cibie". They are just slightly under 7 inches in diameter and I mounted them where the fog lamps would be on the Volvo Bumper. Took a little cutting as they are round, vs rectangular but the results look good.
E-spec lights have a very definitive cut off, have much better optics and reflectors, give a lot of light to the side. I went to the Volvo dealer and got a couple of extra switches (27$ a piece - I gotta find a salvage yard somewhere close by) and wired the lamps so when the normal low beams are on, I can have these on or off, and when the high beams are on, I have the option of using the e-spec lamps or not.
After 2600 miles and a lot at night. Great addition. No one flashed me when I had both sets of low beams on, and I a lot more light going down the road.
for lights (Gunther is the contact - good guy and very knowledgeable)
Somewhere I have a link to an excellent article on e-spec lights but I think it is in my volvo which is 1600 miles from me, as I am back in Mn for a couple of weeks.