AA batteries can supply plenty current, the question is for how long.
You need about 1.3 Watt for 30 LEDs (I’m assuming 15 mA, 3V). A rechargable AA battery has about 2.4 Wh according to Wikipedia, so 6 AA batteries will last you 2.4Wh * 6 / 1.3W = 11 hours.
I have no idea how curing works, but 1.3 Watt feels very low. That amount of power is fine for visual lighting, or for signals (turn on a TV), but energy wise it’s very little.
I would make sure the solder connection between wire and resistor is very solid, and then encase the stuff in heat shrink tubing with glue in it. (Adhesive Lined Heat Shrink Tubing)
If it’s good enough for Nasa, it will work for your car: https://makezine.com/article/technology/computers-mobile/how-to-splice-wire-to-nasa-standards/