Sorry to hear you're getting rid of the Panda
On a 306, you might find that there's a few electrical problems, as John H mentioned. When the alarm doesn't work, you'll see what we mean.
For starters, the airbag warning light will stay illuminated, when it should go out. The problem here is that the plug for it is underneath the drivers seat, and if that has been moved on the rails (or lifted up on a 3dr car) the wires have worn loose.
Next thing is the radio that will inevitably fail for no apparent reason. The radio is a Blaupunkt 3030 jobby in a 1993-1997 car, and a Clarion one in the April 1997 onwards facelifted car. If you should want to swap this, there is an adaptor that can be bought so that standard shaped units can be fitted.
Thankfully, the 75bhp 1360cc unit in your 306 is a fairly reliable XU series engine and has also appeared in the 106, 205, 206, 309 and 405, so sourcing spares shouldn't be a problem.
Which model 306 is it? A 1993-1997 XN, XL, XR, or a 1997 onwards LX?