Hi ZXRJohn,
The mod to the lift mechanism is really simple, no adapters required. The drive gear from the Peugeot lift motor is removed, it looks like two gears one on top of the other. Carefully grind down the teeth on a bench grinder the larger gear off the two. Although the spline count is different , the Peugeot is coarse, the Audi fine. Keep carefully grinding until the gear starts to engage in the Audi splines. Now come the the magic, the Audi housing has a 6mm hole in the back of the housing .Put a 6mm bolt in the vice that is long enough to pass through the Audi housing and the Peugeot drive gear and space for a nut. Then get the gear red hot, drop it on to the bolt quickly put on the nut and then tighten the nut with a fully charged powerful cordless drill. Once fully seated cool the gear with water.
I know it sounds long winded but it worked for me.