Will this fit under my car, or do I need a lift?

This creeper is designed for low-entry work — it'll slide under most vehicles without a lift. Test-fit it under your car's lowest clearance points before your first job to confirm it works with your specific model's ground clearance.

How do I know if the concave shape will actually work for my body type?

The 40" length accommodates most drivers. The concave curve is engineered to support your spine, but if you're taller than 6'4" or have a very wide frame, your elbows or shoulders might feel crowded — test it in person if possible before committing.

What kind of wheels does this have, and will they roll smoothly on concrete and asphalt?

Wheel specifications aren't detailed in the product data — contact support for wheel material, diameter, and rolling surface compatibility before purchase.