Driveshaft U-joint lubrication in '93 S4

[RJA]

Just bought a '93 S4 and would like to lubricate the center U-joint as
preventive maintenance.  According to the dealer microfiche there is a
grease fitting on the U-joint (like the earlier 200's) but my Bentley manual
for the S4 does not show any grease fittings.  Sure would be nice to know
definitively without having to pull off the exhaust and the protective
shield -- any BTDT??

-- Rich
   '93 S4
   '90 200q (soon for sale)
   '83 Coupe GT