What he makes will depend on
1. His training and certifications – apparently that looks good
2. The work he’s asked to do – and apparently he’s working on the higher-tech stuff
3. The dealership – and “Lexus” doesn’t mean as much as “the owner” (and the condition of the place – if it’s spic and span clean, shipshape and high-polish, then that’s a good sign, too)
4. How good a starting salary he negotiated and any prior experience he had. If this is his first job, then he may be working for relatively less than others in the comparable position, but paid less simply because it’s his first job.
But all told, I would think that he’s earning an above-average salary, and with the overtime he should be making a decent income.
But that’s just “income”. Then there’s the question of how he lives and any debts and obligations he has:
1. Student loans
2. Rent (even if he lives with his parents)
3. Insurance premiums – and car payments, if he felt rich and bought a new car, for example
4. Other obligations – does he have any children that you know of, whether with an ex-wife or ex-girlfriend? Child support is very expensive, and more so if he’s making good money.