Which laser mode works best for checking body panel alignment?

Cross-line mode gives you horizontal and vertical references at once—best for verifying panel gaps and door fit. Single-line mode works if you're checking one axis at a time.

Does the 8ft tape lock in place while measuring?

Standard tape measure operation applies—pull the tape to length and it'll stay extended under spring tension until you retract it manually.

Can I use the laser outdoors in daylight?

Laser visibility drops significantly in direct sunlight. Indoor shop work and shaded areas are where you'll see a crisp line; use the tape function outdoors instead.