shocks

[transporter]

Do you need to change shocks as well if you use say 30mm lowering springs.

[caledonianewan]

i think up to 40mm is ok with the same shocks

[mixmatch]

Its up to you if stiffened lowered springs with original shock are still too soft then you'll want stiffer shocks to get the desired result but when lowering you will need to have the camber adjusted, and if the wheels are bigger then original you will have to shim / pack the bump stop to make sure that the top of the wheel doesn't catch the wheel arch when cornering (front wheel sticks out and body roll compresses the shock on the outside of the corner).

Personally the hassel in lowering a car/van propperly along with not being able to corner as hard just isn't worth the improvement in apearance.
but thats only my opinion.

[transporter]

Its on 2006 caravelle and vw sell springs 30mm less than original ,but doesn,t mention shocks .