Get something that can take a beating
Bigger is definitely not better
Not only are bigger cars with bigger engines going to be more expensive to both buy and insure, but they are also far less safe. Your teenager might be the safest, most trustworthy kid on the road, but if their car has a powerful engine, they're going to want to open it up. Something like single litre engine is far better since it prevents them from being able to get up to ridiculous speeds and greatly reduces the temptation to drive dangerously.
Don't be afraid to ask for advice.
No matter what car you get for them, remember that this is an incredibly important stage in your teenager's life. Make sure that you're allowing them the freedom that they need. It's still important to set rules for them, but it's a good idea to show your teenager that you trust them behind the wheel. By doing that, they're far more likely to be a more responsible and safe driver.
** This is a collaborative post