Is under car shield on new beetle necessary?

no

It's likely there to help manage airflow under the car. Probably to help gas mileage and higher-speed stability issues. It may well also impact temperatures inside the engine compartment. No vehicle maker puts something like that on there without a reason, if only because anything added increases cost. It's likely you can get away with it not being on there without something "bad" happening.

Right. Not essential but VW did have a reason. My Eurovan has one and those of us EV owners that have removed it have noticed that the car runs a little hotter w/o it. It also serves some sound dampening function as well.

It's mainly for sound insulation.

It was added to help meet strict drive-by noise restrictions of Switzerland and other EU countries.

Those are now available cheap on the aftermarket. Motormite Help! makes it as part number 41098, about $25 - $30

- - Rex Burkheimer WM Automotive Fort Worth TX

snipped-for-privacy@webtv.net wrote:

I would be real surprised if it doesn't make a big contribution to cooling efficiency.

- - Rex Burkheimer WM Automotive Fort Worth TX

Patrick Owen wrote:

I am going to guess it might be there for streamlining.

It depends on what you mean by necessary. Will something blow up? No. Will cooling be effected? Probably not. Will there be water in places that are not supposed to have water? Most certainly. Will your economy suffer greatly? Oh yeah.

I lost the shield on my 2002 Jetta TDI. The temp gage never varied but I lost 5 - 8 mpg in fuel economy. I also suspect there would be things getting water soaked that are not supposed to be, so I would suggest you replace it, especially if you're the least bit interested in fuel economy. Cheers, jc

A steel replacement is available from the dealer, you can also find additional ones either in steel or thick aluminum online. It serves to protect your aluminum oilpan, depending where you live this may or not be necessary.

Ever wonder why you lost the old one? Probably hit something pretty big on the road. I've got a lot of battle scars on mine and know that I would have toasted at least one oilpan on our nasty roads if I didn't have it. Loss of oil = blown engine if run for even a few minutes under that condition.