i wouldnt run one as said the engines contain that amount of oil for a reason, if i was going to run one ide be doing oil services every 4-5k atleast
involved its just a case of buying the new sump and replacing, ide replace the pick up pipe while you have sump off.
some mk4s (think its only 2 out of the 3 mk4 engine codes but could be wrong) have a sensor on the sump i belive?