Evaluate the operations inside the first set of parentheses.

First, perform the multiplication:

$$0.78 \times 12.46 = 9.7188$$

Then, perform the subtraction:

$$9.7188 - 2.03 = 7.6888$$

The first part of the expression becomes:

$$7.6888 \div 0.52$$

Perform the addition:

$$7.201 + 2.554 = 9.755$$

The second part of the expression becomes:

$$45.12 \times 9.755$$

For the first part:

$$7.6888 \div 0.52 = 14.7861538...$$

For the second part:

$$45.12 \times 9.755 = 440.1996$$

The fourth decimal place is 7, so we round up the third decimal place.

$$454.9857538... \approx 454.986$$

The evaluated expression rounded to 3 decimal places is $\boxed{454.986}$.