There's an achievement/trophy for getting five kills by sabotaging a vehicle, and having it blow up and kill an enemy. The game is a bit finicky when it comes to counting these kills — it didn't work with an ATV in another spot, for instance — but I found a foolproof place to grind these out.
First, make sure you have the sabotage perk and make sure you have the difficulty set to easy. I'd also recommend crafting the homeopathic for incurring less damage, but that's up to you.
In Faith's region, go to the trailer park to get Sharky, the flamethrower-wielding Gun for Hire. Talking to him starts a mission called "Burn, Baby, Burn", where he lures cultist Angels in by playing the song "Disco Inferno". You're then tasked with clearing out the Angels.
You can try the trick during the first wave, when it's just a few angels here and there, but I found it worked best when Sharky gets overwhelmed and you're required to shut off the speakers in four different parts of the trailer park. At this point, swarms of the Angels come out and keep spawning until you switch off the last speaker.
Directly across from Sharky's perch is a vehicle spawning station. Once the Angels start to swarm, make a beeline for the vehicle spawn and request a vehicle. I just happened to choose a tractor, which worked out great because it's larger and will help shield you from the Angels. Go to the front/hood of the vehicle, hit
to sabotage, and then run in a circle around the vehicle while the Angels are swarming. You might be able to get multiple with one explosion, but the Angels have weird hitboxes — the amount of damage to kill one may not be the same amount to kill another. Luckily, you can just repeat this method to get your five kills, shut off the speakers, and complete the mission.