Any one of the common problems can go Murphy on you at any time. If you are the average driver you scratch your head, call a tow truck and give him your address or your favorite garage.

*Incurring an hours diagnostics (way optimistic)
*an hours labor
*the invoice cost of part

Just this one breakdown has cost more than the 4 most problematic fixes plus a code reader.

Preventative maintenance is preventative spending.