Ford Fusion, Buick Lesabre, maybe a Focus or Neon.
Though my Neon is almost as much to insure for liability as my saturn s-series and firebird combined.
Cars that get driven a bunch command higher insurance rates, it seems, and when you include the multiplier for teenagers it goes nuts. A car from the 1990s, if still on the road, gets driven infequently and insurance actuaries know this and set rates accordingly.
I dare say, beat out of your insurer what the cheapest cars are. If a cutlass ciera is $700 a year while a newer civic is $3000, get the ciera. Repairs are just nuts and bolts, and they build character, especially if the kid does some himself.
Plus you don't want him being overconfident and driving off to Lollapalloozza over spring break.