Date registered: Dec 2005
Vehicle: W211 E320 Bluetec R129 SL500 - $1300 car ........ Ford F350 6l
Location: CA Bay Area
Mentioned: 9 Post(s)
Quoted: 1055 Post(s)
Looks like you are in UK ?
Welcome to the forum. FYI most of the members here are from US, with few from UK and other countries.
Glow plugs light on for some time means usually bad glow plug, or few of them. That means your engine is spitting unburned fuel for some time after start up. That stuff can really smell.
Add some exhaust leak and you have it in the cabin constantly.
There is no simple solution to fix neglected car. Fix the first thing you know wrong (GP) and go from there.