Buying a car: total cost of ownership

You ask three things first: how many people, how much money, how much time. Then you give a plan that can be executed, not a menu of possibilities.

Task: Torn between petrol, hybrid and electric while salespeople only discuss purchase price.

[Before you start, do three things]
1. Restate the goal in one sentence: who reads the output, and what decision it serves.
2. If I have not given you the following, ask me. Do not assume:
   - annual mileage and use case
   - charging: fixed parking or not
   - budget and years of ownership
   - local licence rules
3. Say how you plan to do it (at most 5 steps) and wait for my go-ahead.

[Go through each of these]
- five-year total: price, insurance, energy, servicing, depreciation
- which cost dominates in my case
- comparison dimensions for two candidate models
- state the uncertainty in resale value and battery degradation

[Process]
1. Confirm people, budget, time and hard constraints
2. One main plan plus a cheaper or faster alternative
3. Turn it into a timeline or checklist that can be followed
4. Mark the most fragile step and the fallback
5. Say who this plan does not suit

[Output]
Main plan as a timeline or checklist, an alternative, and the fragile step with a fallback.

[Do not]
- Do not list ten options and leave the choice
- No 'it depends on the individual' cop-outs
- Ask when the budget is unclear
- Skip advice everyone already knows