The're ways to minimize that.
First, the so-called noise barrier (hahahaha) put in by Dacia under the bonnet is really just for visual purposes.
1) unclip this black cloth thing.
2) degrease the inner metal of the bonnet : don't skip on this if you want to avoid problems with step 3.
3) apply Alubutyl sheets there (don't worry, they won't fall off when applied correctly on a degreased surface)
4) on top of that alubutyl, put a good layer of sound deadening material that's temperature/oil resistant and designed for use "under the bonnet/in the motor compartment"
5) clip the official noise barrier back in place
6) take off the under metal engine protection plate. If you don't have a chrome front bar, it's very easy to do. If you have the chrome bar, it IS possible to do it without taking the chrome bar off, but it's .... fiddly.
7) degrease it
8) put in a layer of the same Alubutyl, making sure you cut out the holes for oil/water present in the metal plate
9) use the same oil/temperature resistant material on top of that (-> the Lodgy uses the same trick standard "from factory")
10) and place the whole thing back
If need be, you can still use a lead-lined engine blanket from Noisekiller placed "over" your engine, between engine and firewall. Don't fear overheating, your engine still gets more than enough fresh air. But even without the blanket and just by insulating bonnet and under metal plate, you'll find the sound of the diesel engine has lowered significantly.
If you want to get quieter still, you'll need to get under the carpet inside the car, and remove it at the footarea. Normally, you'll find a piece of styrofoam (not joking) underneath. Remove it, but do not discard it, you'll have to place it back. The inside of the firewall is covered with a rubbery-feeling material, which is screwed to the firewall. Loosen the screws so you can get underneath. Stick Alubutyl as high as possible underneath it. Cover the Wheel arches while your at it too. Use sound-deadening material at your own discression under there too.
Fix everything back in place.
As a last step, you can shove sound isolation material "as high as possible" up under the dashboard on passenger and drivers' side. Be careful with the heating pipes and varioius tubes and lines though.
It's half a day worth of work, but having a car that drives a lot quieter for the next 5 to 10 years is well worth the time and money spended, and the material cost is negligable.
