Update parking in Gent.
If you want to park as close as possible to St Bavo’s Cathedral, Parking Zuid (P3) is a good option too. Driving along and coming from Brussels on the freeway E40 follow direction E17 – Kortrijk – Antwerpen – Gent at intersection Zwijnaarde. Then keep following Gent –Centrum B401 for about 4km. At the end of the park and staying on the left lane you will drive straight into Parking Zuid (P3), practice a bit with Google Streetview.
You will see also signs for Parking Reep (P2), but do that only if you are confident with the traffic in Gent. There are some roadworks going on for the moment and no garantuee it will be easy with al those one way streets leaving Gent without loosing serious time.
Parking Zuid - at street level there is a bus and tram stop with direct connection to the cathedral, best place is getting out at Gent Duivelsteen close to the backside of the cathedral. Walking this half mile distance will need about 10 to 15 min.
For getting out of Parking Zuid follow exit (there are several exit’s) Franklin Rooseveltlaan E17 E40 for going straight to the freeways south of Gent.
Nevertheless parking near Gent-Sint-Pieters as explained before remains to my opinion the most hassle-free option (+ storing your luggage and visiting MSK) if not familiar with driving through Gent.