QUOTE(quinophex @ 13 Feb 2010, 18:55 )

Main differences between a linear and a vector (usually anyhow, there are exceptions!).
Generally the Vector has larger alloy wheels, body colour bumpers, body colour trims & inserts etc. Climate control, extra interior trim, leather seats, uprated stereo, cup holder the linear is more of a base spec but some may have had extra options added to them. Usually the Vector would be far higher spec than a linear.
That will earn you a WRONG BONG!
On a 2003-2006 9-3, the standard stereo option on ALL 9-3 Variants was the ES1-4, no in dash screen (the radio information was given in the small screen on top of the dash) and 4 very poor speakers. Upgrades on all variants include 7 or 13 speaker outputs probably different wattages too... giving you ES1-7 or ES1-13. Another option was the an in-dash mono screen (ES2-4, ES2-7 or ES2-13) and if you really had £2000 to waste you had the full colour screen with in-built SatNav (ES3-13). Linears are most likely to have the ES1-4 systems, whereas in Vector, Arc and Aero models you have a better chance of ES2-4 or ES2-7.
You will see numerous threads commenting on how poor the 9-3 audio is and ways of improving it, if you do end up with a 4-speaker (or 7-speaker) car..
The earliest Vectors (52 or 03) are likely to have Sports Suspension fitted, making it firmer. Later ones are tamer...
Vectors have part leather part cloth trim too.