From the A2 Wikipedia article...
Special versions
Audi also has a version of the A2 in its Neckarsulm plant which has been converted into a
pickup truck by trainees – the "A2 Caddy". This was on public show for the first time at the A2-Club of Germany's annual meeting in
Amberg, Germany, in August 2005. Pictures of the event are available on the German A2-freun.de site linked below.
Audi also released an S-line version in Germany as of late 2002, with 17" 9-spoke "RS4" style wheels (standard were 15"), sports seats with large side bolsters and lumbar support, special half-leather seat coverings with Pearl Nappa leather and Sprint cloth, leather handbrake handle, perforated leather gearstick and 3-spoke steering wheel and 10 mm lowered sports
suspension. Additionally, the interior roof lining, the dashboard and carpets were black, the instrument faces titanium-coloured and an S-line badge was added to the rear doors. The driver information system and illuminated vanity mirrors for driver and passenger completed the package
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In the UK, the last Audi A2s (from early 2005 to June 2005) were badged as special edition models featuring a reduced price tag, digital climate control and a 'Concert II' radio with CD player as standard. They were the only models available in the UK at this time and were available with either the 1.4 petrol or 1.4 TDI engines. This special edition gave the A2 a final sales boost in the UK.
Although Tom has already stated the black headliner was only on the S-Line Plus. Perhaps other items were also on this higher Plus spec?