My 2011 Agile came with a Thetford Aqua Magic V toilet which I've replaced twice with same model due to holding tank fume leakage around the flush valve assembly. The last replacement lasted about 2 years of use then it started to leak fumes again!
Thetford Aqua Magic V design is not very well thought-out IMHO; the space between the toilet bowl and the toilet outer casing/base is hollow and open to the black tank. Waste splatter can get stuck in that hollow space during flushing, very unhygienic. The flusher arm seal is also unreliable, it is basically sealed with packed grease. When grease seal starts to dry up, it starts to leak fumes from the holding tank especially when there is negative pressure inside the van like driving with windows open.
