Previously I have posted about decoding UrS4/S6, S6 Plus, S2 and RS2 VINs and Build Tags: http://www.s2forum.com/forum/showthr...+tag+locations
These are the tags that contain the codes used in the build of your UrS car. The location is different for the UrS4 and UrS6 sedans, S2 coupes and RS2s. S6 plus is probably the same as the UrS6 since they were built in for the 1997 model year. This post will help to locate your car's build tag.
Here is what they look like (but without the red boxes and the yellow lettering):

Here is where they hide:
UrS4s:

UrS6 Sedans (and maybe avants):

Here is one in a 96 Euro A6 TDi Avant:

UrS6 Avant (one location):

(photo courtesy of rew)
UrS6 Avant (another location):

Here is an example of the location of an RS2 build tag, in the spare wheel well, like the UrS6 sedans, etc.

B3 Coupe Quattro/S2 Coupe tags are under the stowage box in the trunk/cargo area, as shown here:

Base photos courtesy of Mario P. from the Bronx, aka Audidicted
There should also be a build tag in the Warrany Service book,
Here is one from a RHD 1994 UrS4 autobox in New Zealand:

Photo courtesy of vbmica in New Zealand.
Here is one from an RS2:

Decoding the VIN and build tag codes is also discussed HERE
These are the tags that contain the codes used in the build of your UrS car. The location is different for the UrS4 and UrS6 sedans, S2 coupes and RS2s. S6 plus is probably the same as the UrS6 since they were built in for the 1997 model year. This post will help to locate your car's build tag.
Here is what they look like (but without the red boxes and the yellow lettering):

Here is where they hide:
UrS4s:
UrS6 Sedans (and maybe avants):

Here is one in a 96 Euro A6 TDi Avant:

UrS6 Avant (one location):

(photo courtesy of rew)
UrS6 Avant (another location):

Here is an example of the location of an RS2 build tag, in the spare wheel well, like the UrS6 sedans, etc.

B3 Coupe Quattro/S2 Coupe tags are under the stowage box in the trunk/cargo area, as shown here:

Base photos courtesy of Mario P. from the Bronx, aka Audidicted
There should also be a build tag in the Warrany Service book,
Here is one from a RHD 1994 UrS4 autobox in New Zealand:

Photo courtesy of vbmica in New Zealand.
Here is one from an RS2:

Decoding the VIN and build tag codes is also discussed HERE