The following is a way to tell the different year A4'

The following is a way to tell the different year A4's apart from each other. The first table shows the quickest way to distinguish a particular year. The second is picture based to show the actual differences.

96	Wide rear license plate area
97	Amber taillights and small passenger mirror
98
98.5	Red taillights ver.1 and small passenger mirror
99	Red taillights ver.1 and full size passenger mirror
99.5	Many changes incl. new lights(Red taillights ver.2) and lowered badges
00	Same as 99.5, but with diff. sport rims and stereo
01	Same as '00, but with 170 HP 1.8T and red mark on 1.8T badge

Yr	01	00	99.5	99	98.5	98	97	96
Headlight	Xenon Avail.	Xenon Avail.
Side Light
Taillight
Badge Location
Pass. Mirror
License Plate
1.8T Wheel						1.8T N/A		1.8T N/A
1.8T Sport Wheel						1.8T N/A		1.8T N/A
2.8 Wheel
2.8 Sport Wheel								Sport Wheel N/A
Avant	1.8T & 2.8	1.8T & 2.8	1.8T & 2.8	1.8T & 2.8	2.8	2.8	Avant N/A	Avant N/A
1.8T Engine	170 HP	150 HP	150 HP	150 HP	150 HP	1.8T N/A	150 HP	1.8T N/A
2.8 Engine	30V, 190 HP	30V, 190 HP	30V, 190 HP	30V, 190 HP	30V, 190 HP	30V, 190 HP	12V, 172 HP	12V, 172 HP
Yr	01	00	99.5	99	98.5	98	97	96

96 and 97 only had "standard" shocks. There was no sport suspension.

In mid '97 (before the time when the next-year's models typically become available), Audi put the new 30V V6 into the (otherwise) '97 2.8 and sold it as a '98. This is what we know the '98 or the "early '98" to be. When the fall came around and the next-year-model became available (both 1.8T & 2.8), there were a variety of changes made to the interior and exterior of the car. These vehicles are the ones we know as '98.5.

The '99 started at the normal time and part way through the year changes were made. These new vehicles (1.8T & 2.8) were known as 99.5.