Once you get to the border/gretna head onto the A75 to dumfries then up the A76 all the way to kilmarnock then take the A71 heading west to Irvine where you youll pick up the A78 takes you all the way up the west coast where you can get over the erskine bridge..its a more scenic route than pounding the motorway and you avoid Glasgow ..
Good tip that, thanks.