An unfortunate crash-landing

When the bars on his window are wrenched off by a flying-carful of Weasleys, Harry is glad to be free of the Dursleys. But a malfunctioning Ford Anglia means that the four of them never make it to Ottery St Catchpole- instead, they crash-land in Severus Snape's garden. Based on a Potions and Snitches challenge, also posted on P&S.