We've just moved back to the D4 after running the Durango and the Cat.
I'd forgot how good this car is. and at the last national had my best national result ever with a 4/5 year old car!
As it is, it is a very good car. We've made a couple of simple mods to the top deck etc. but otherwise its basic.
There are a few improvement to come but we'll have to wait to get them on the cars.
Well worth the change.