I think I used a spray trim adhesive on mine.  Auto parts stores have
this type of product.

The tried and true and what factory used is Yellow Weatherstrip Adhesive
made by 3M or Permatex... sold in tube and you will need two of them. You
can get this at any Pep Boys or autoparts stores.

The spray type that other people mentioned is Super 90 by 3M... this you can
get at Home Depot... but I never used this for hood.. only other stuff not
subjected to heat.

3m makes a high temp spray adhesive.
Peter

JC Whitney also sells a high temp sparay adhesive. I bought some for another
project on my replica car but I have not used it yet.
Peter

I replaced my hood pad on my 1987 300E two years ago.  I used 3M Super
Trim Adhesive (yellow) Part No. 08090 in a spray can.  The can has a
fairly high tech spray nozzle that controls the spray very well.

Clean the old material off he underside of the hood as well as you can
so you are re-glueing to metal, not crusty old pad material.  I used a
wire brush to make sure anything left I was glueing to was stuck to the
metal well.  I wiped it with paint thinner (exact same product as parts
cleaning solvent in the "old days' when I worked for Union 76).  I
masked off around the hood and covered the windshield and engine, but
the #M nozzle made it pretty much unnecessary.

The secret is to spray both the pad and the underhood and wait the 10
minutes or so just as the directions on the car tell all of us impatient
people to do.

Make sure you have it aligned correctly since the adhesive will stick
immediately and never let go.  I marked the middle and attached at the
bottom of the hood at the cowl and pushed it up to center it at the top
front grill then smoothed it outward at the bottom and out to the sides
of the hood.  I used a small paint roller to push it into contact
evenly.

Not a hard job. Cleaning all the old stuff off is a nasty job that most
shops will try to avoid by quoting an outrageous price. Not to mention
the come-back if it falls off.

Pete Cowper (1987 300E)

Where did you get your hood pad........I need one for my 1997 SL500??

I paid $86.10 at the Fresno Mercedes dealer for a 1987 300E hood pad in
July 2003.

I would be wary of aftermarket pads that may quickly crumble all over
the engine and require re-doing the whole job.  Some parts are best
bought at the dealer if the price differential is not too great.

"The satisfaction of high quality lasts much longer than the elation of
low price."

Pete Cowper (1987 300E)