The OVP is behind the battery. It's a tall square unit. If the last four digits of the part number are 52 45 and it says "Made in Austria" replace it. The 52 45's are known trouble-makers and I suggest replacing them even if all is well with the vehicle. It's only a matter of time before they go bad. It's easy to replace for a DIYer. If the last four digits of the part number are 67 45, you have the updated OVP and just check the fuses.
If you need to find the throttle body, then perhaps you should get yourself a publication like Haynes that has a lot of good information with illustrations.
95 E320 Cabriolet, 131K