Windex will kill them on contact when sprayed directly on them but has no residual effect. Works good when they invade an area you don't want to use pesticide on. In addition to climbing up tires, stabilizers/jacks, hoses, etc., look above rig for small limbs that might be touching roof as a path for them.
We've discovered when we have boat tied off to shore and leave snacks onboard, ants will crawl out shoreline and invade boat. I've started tying weight to line to hold it down in the water.