will changing the stock high tension wires to thicker after market ones improve the performance of the A4? which brand is recommended?

If so yes they reduce the roll considerably...Neuspeed makes some very nice ones for a reasonable price...if you have the sport package don't waste you time with the front...but buy the rear bar when you get a chance.

Regards,

James R.

2001 A4 1.8TQMSXP (Oettinger Pedals, Oettinger RE's 17x8 Yoko AVS Sports 225/45/R17, Euro Xenon Housings, Bailey BPV, MC Intake and RS4 Grille)

old school term hehe
and to answer your question...i dunno sorry