..okay ive been plagued by my nuvi550 for a while as it dosent show the fuel stations...folks offered advice but i couldnt solve it till today 
As the nuvi only has 1.8gb harddrive it wont hold the huge 3.8gb whole of europe mapping so I ve used the sd card it the mapping is fine and dandy, but for some strange reason [too much red wine] I decided to transfer some of the countries I regulary use via mapsource to the harddrive on nuvi550...removed the card and bam di a normal where too then fuel and instead of bloody mccolls and smiths I got before it now shows only fuel stations so im a happy Bunny...
so maybe by running garmins from only the sd card and not the harddrive we arent getting the full chocolate experience...maybe this helps some one
...now to fill the sd card with gpx routes and topo maps .
