Cream accumulates on oil filler cap in cold damp weather.
Pedal rubbers are noticeably wearing.
Incorrect headlamp fitted - had to be replaced.
Fuse kept blowing when opening tailgate due to faulty connection to rear no. plate light.
Spare tyre had lump of metal stuck in side, replaced under warranty (trim clip carelessly left in well).
Bought as a workhorse replacement for Cavalier. Nippier (due to lower gearing).
Pulls trailer full of bikes plus cabin full of people well, and is OK with caravan too.
Even with this engine can be fun to drive, but I get lots of road noise which is tiresome on a long journey with the windows shut, but is not noticeable with them open.
Seating now comfortable, but takes getting used to and needs careful adjustment.
Fuel consumption is about same as old 1.8 Cavalier, had expected it to be a bit better.
Load space very useful (it's what I bought it for), and loading does not seem to impair drive-ability as long as you put lots of air in the back tyres.
I do a 60-mile round trip commute on M5, M6, M54 and apart from road noise does the job well.
I had a '93 Astra 1.4LSi which has a similar engine design to the 1.6 8v in your car and my car also had cream forming under the oil filler cap in cold damp weather. This is probably nothing to worry about, simply some water (resulting from the combustion cycle) collecting in the oil and congealing to form the gunk you see on the filler cap. In some circumstances the gunk can point to head gasket, but it sounds more like the former "problem" to me. Nothing really to worry about. Hope this helps.
I too have a 2001 Mk. 4 1.6 8-valve Estate. Same happening, but really nothing to worry about. Just whip the cream out and mix it with tuna fish (only joking!) Think it fair to mention though that despite the long service intervals given in the handbook schedule, all Vauxhall OHC engines from the late 80s onwards do benefit greatly from frequent oil changes.