The Mauritanian border is the worst..both with western sahara and senegal...like i say you`ll need 5 and 10 euro notes..you pay 10 euros to all,customs..border guards and police..its possible to negotiate if you speak good french..otherwise..its best to just be patient and pay up..we waited 3.5 hours at the border entering mauritania near nouadihibou..all ok just watch the soft sand in no mans land between the customs posts..youlll easily get stuck if you follow the normal route its terrible..there are other routes through but be carefull coz apparently it was mined and a cyclist got blown up taking a short cut..Well thats the story...i just followed a local car through and was ok....Now then..as to entering Senegal..I advise you to avoid the Rosso border at all costs..there are police marching around doing their best to screw any foreigners they find out of as much as possible..and i know i spent half a day being intimidated and marched around by a young buck policeman in dark shades..its not pleasant at Rossi mate... i would have like to have met that cop out on the dirt i tell you..but anyway..the other border is near to Rosso ..but not as near as the map says..it looks like 60 km or so on the map but its more like 160 km..its dirt track but ok..an old railway track way i think...The track to the St Louis crossing starts just as you aproach Rosso..just after the first petrol station..and bfore you get into the village of Rosso proper..maybe a few hundred yards from the gas station..theres something like a small army garrison on the corner where the track starts..its on your right and just a dirt track no sign...get the Gps cordinates from someone if you have one....avoid Rosso at all costs..the rest is quite easy good luck mate ..safe riding ok Tom