if u use a skycube as a background u could take the skycube+6.tga as a reflective map on your model (by assigning a shader).

check out this threads about skycubes:
how to place a skycube into a lvl
how to make a skycube-tga with Terragen
free skycube-tga

to assign the shader to the model i use SMEE2
i think its a really good tool to make shaders
get it here
if u dont want to make the shader yourself im sure u will find some free ones in this forum...

Note that the model will only reflect the background and not other models, like terrain, trees, houses, etc...

if u really want to make a reflective material, it's gonna take a lot of system power... just to reflect the background is a good fake though...

i hope this helps a little

cheers sinnlos