My car slowly drips oil from the drain plug and between the tranny and engine, at least, according to the mechanic. An unnecessary 1600$ repair. Do you think a belly pan would be helpful to at least keep the driveway clean. I mean so it would catch the drips. What do you think?
An oil leak from the drain plug can be fixed for a few cents - it will just need a new crush washer on the plug (somthing that ought to be replaced every time the oil is changed, but rarely is).
If it is leaking from between the transmission and the engine you've got a bigger problem, and one I would get fixed regardless of the fact it makes a mess, as it'll ruin your clutch/torque converter. It will be either the oil seal on the back of the engine or the one on the front of the gearbox - you ought to be able to tell by the smell whether it is engine oil or transmission fluid.
Fitting a pan to cacth the drips will only hide the problem - and run either engine or transmission without oil and you'll soon end up with a much more expensive problem!