I can't remember many design niggles with my old Clio, apart from the fact it was generally cheap, old, slow and small (though this did make it easy to park). One thing about it was if you revved it a little bit you would hear this funny tooting noise coming from the engine, it wasn't too alarming and it wasn't a real problem, but I never worked out quite what it was, it must have been an airpipe or something. The worst thing about my car was that the battery would go flat rather quickly, there were times where I really wasn't using the car very much (which meant the engine wasn't recharging the battery enough), but it had an aftermarket burglar alarm and immobiliser (came with it when I bought it) I think this was too much of a drain on the battery, because my parents cars both had alarms and immobilisers but they never went flat, even if you left them for a week. Also that alarm was quite sensitive, so if a slightly noisy car went past the house (people in England don't always drive qently through streets) it would beep (like a little warning rather than the alarm going off). Whenever it was parked outside my parent's house, if my dad got his Harley out that would definetely set it off, soon I just stopped activating the alarm when I parked it at home, I would just lock it manually with the key.

My dad has a Seat Leon (the model before the newest one) and I really don't like that car, it's very boring but worst of all it has this stupid locking system, so whenever I go somewhere with my mum, she presses the button on the key, and I pull the passenger door handle but it doesn't open, so I have to remind to her to press it again so it unlocks the whole car rather than just the driver's door (she always forgets this, you know what mothers can be like at times), it's so annoying.