Routine maintenance and promptly fix things as they break/wear out.
Our 93 Suburban turned over 350k this week - my old friend has certainly been a nice vehicle to maintain. Hoping it will out live me!!

 

Lucky to still have most of the vehicles I've owned since the late 70's , always doing all of the above and then some ..... maintenence wise

Family members over the years often asked if I 'was working on that car again' and never did understand the maintenance routine that has kept me busy thinkering , learning and saving money instead of buying new cars every 5-10 years like a lot of people I know

Our '82 Chevy van has a million Kms on the body by criss crossing Canada and the US over the years , the '83 Caprice and '80 Impala come close , the older ones in the barn probably even more ..... ehehe

Replacing parts way before they break on these older cars is quite easy and inexpensive , as well as replacing all the fluids regularly and keeping everything lubed and greased

Personal pet peeve , when I take something apart I always use silver Antiseize on the thread of the bolts , nuts , screws etc.
Over the years it's always been an easy task to replace something even in the middle of nowhere with
a basic 1/2 and a 9/16 socket/wrench since everything has been antiseized

Our newer chevy's have a good mix of both metric and standard bolts , and that drives me nuts (pun intended)

Keep 'em greased , keep 'em rolling ....... Cheers ...... Vinny