Difference in road noise with and without the under cover

We just finally got our 2010, love it, and are now trying to make it as nice as possible.

The model we bought - the S (second from bottom Japan model) - does not include the underbody cover. We weighed the price difference between buying the next model up and the S and didn`t feel that it was worth it just to get the underbody cover. Too much additional stuff we didn`t really need or want.

Has anyone driven around without the cover? Were things noisier or was there no perceptible difference?

The car is fairly quiet, but we wonder if it would be worth it to pay for and have the underbody cover attached...? I know that it has an effect on the mileage, etc - but we`re more concerned with any differences in noise level.
We were thinking of adding some deadening, but if the underbody cover provides a fair amount of road noise reduction and is cheaper... well, we could probably add the cover and a minimal amount of deadening to get a good result without spending much more (and get the other bonuses of the cover). If there is very little difference when it comes to road noise, then we won`t bother with the cover.

 

It isn`t ALL the cover that isn`t included. I believe it`s just the under body cover - the under engine cover is standard on all the models. From what I understand the cover is split into 3 different parts, the under engine cover, under body cover, and a cover for under the back area. I`ll have to try to get a picture of the underside of our car to see where there are and aren`t covers.

I don`t think the fleet cars in the US have all 3 parts either. The very lowest model that isn`t sold to normal consumers doesn`t, if I`m not mistaken.

I too thought they all came with the full set of covers, but after putting in the order for ours found that the S also doesn`t. All the higher models do include it. We decided not to go for the higher model as it just costs more for a bunch of stuff we don`t need - like cruise control, aero parts, etc. You can buy it extra, but it comes in a set with rear aero parts - something we don`t need. The car is low enough as it is...

I honestly don`t think there is a huge difference when it comes to actual mileage as all the Japanese tests for mileage are done on the L model, which is the one below the S - and it doesn`t include those extra covers either.
The dealer (they`re actually trained and know what they`re talking about here) said that the additional covers do reduce drag a tiny bit, but in terms of mileage it is pretty much offset by the weight of it. The important one is the under engine cover (included on all models).

I guess I should have been clearer in the way I wrote it. The under engine cover and under body cover are different things.

 

Almost right. There are three under covers. The under engine cover - under the front and engine. Then under floor cover, center and rear. Center is, well, center. Rear is the black plastic below the back bumper. The spoiler listed as equipment for the S Touring, etc, is actually a spoiler. It attaches to the back bumper and is the same color as the car. Like this. I don`t know if it is standard outside Japan.

 

Thank you so much for testing this.
Maybe the weight of the covers matches the amount of improvement....