Ok, in all seriousness. I was joking a "little" bit before, but I imagine you drive your car very hard, stepping on it at each light, not letting it warm up, etc. That will affect your fuel mileage as well.
To make up for it, I have attached some items that might help you gain some hp and looks at the local bowling alley hang out on Sat night...
[URL=http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=50447&item=7966554255&rd=1[/URL]
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33633&item=7966022984&rd=1&ssPageName=WDVW
For the above, I think the visual effect alone would help
Someone was asking about a turbo for the w124... HERE you go, thank me later. This is good enough even for my W124
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=42610&item=7967277862&rd=1
Bare with me... last upgade..make it two more 
http://www.speedshop.org/store/Scripts/prodView.asp?idproduct=92
http://www.autoloc.com/products/flame.lasso
There you go , with all of the above upgrades, your car WILL be peeling out!
