Have previously owned Honda Civics and both did 250,000 miles with no problems. This car has got to 180,000 miles and is self destructing. Every month it is costing me a fortune and it has failed every mot on suspension issues.
First the good points, when its going well, it handles like its on rails, there's loads of grunt in the motor and its fun.
Now the problems.

Engine
Engine egr valves, the car has had 3 so far and I have become a dab hand at changing them, stripping them and freeing up the solenoid to extend the life. A very flawed design.
Turbo boost sensor gums up with blow by through the turbo and needs regular cleaning.
Cylinder 2&3 fuel injector caps both replaced with blue colour factory mod to cure misfires which involves cutting into wiring harness and soldering in new part.
Alternator failed at 170k, have never ever replaced one on car before but this is known fault.
Swirl flap rod on inlet manifold has failed, a known fault and £700 for new inlet manifold fitted.
Clutch failed at 140k and dual mass flywheel also totally shot. Total bill of over £1100 a very common problem. I have never had a flywheel fail before and 140k on a clutch would indicate I'm easy on clutches. This is known fault with these due to poor quality

Suspension
Every mot has seen suspension failures. I drive enthusiastically but my previous Two Honda civics only had one part fail in 500,000 miles. So far four sets of suspension drop links, two front wishbones, set of front struts after one rusted through top mount in inner wing, 2 rear springs, a few other bushes and joints.
Rear brake calliper s have problems and car has rolled away on handbrake when parked. A known issue, do not trust parking brake and leave it in gear.

Bodywork
Not too bad though build quality and panel alignment on all these astra is a bit poor especially round boot line.
Boot catch electric switch comes unglued from mountings and won't open. Glue on the plastic used is a bad idea, either change the plastic type or use mechanical fixing. Solution is to pack wedge behind switch to prevent movement.
Drivers seat frame fallen apart and seat had to be replaced at 150k. I'm not a fat guy and have never had a seat fail but it is apparently a common fault.
Car sometimes would not start with electrics dead. Might take few times to restart. Was also recalled for lights on, horn not working issue. Replacement wiring harness to ecu rectified this and dead ignition issue.
Heater absolutely awful in cold weather. Changed filter but still no better. Takes about 30 miles in sub zero temperatures before it can be turned down. Taken to wearing a coat and apologising to passengers.