Gearbox, handbrake cable, alternator, ignition barrel, clutch, also other general wear and tear things.
A quick sporty car that looks good and handles well. Leather interior and full electrics are added bonuses.
If you want a car with real power, then get an Astra GTE 16v, 156bhp as standard, mine has 210bhp with throttle bodies. Anyway as standard it craps on R19 16v's... Later.
Faster in a straight line, yes. a 19 16v will out handle a stock Astra at the slightest kink in the road. Astra's were not renowned for their handling. Also the 16v variant was only just balanced to the chassis so what you've created by adding more bhp is a death trap. You can take any car and throw tons of cash at it to give bhp however most of the technology to make them handle is done in the design stage.
Get an Astra GTE 16v.
Don't it will be in the scrap yard in 3 years.
They rust as fast.
That's why r19s are still around. Mine just gone though the MOT and passed with no rust. I bet the Astra GTE won't.