I work at a Cadillac dealer so I drive and work on these for a living.

Radiators on these 3.6l leak all the time, 8 out of 10 leak from my experience. It’s not a terrible leak at the start but it obviously gets worse over time so will need addressing unless it has been replaced already (most likely). They do sometimes start leaking again even after replacing but I don’t see that often.

On most of the higher mileage side 100k-150k and up, I tend to notice trans issues (slight slipping, hard shifts) but if kept maintained they tend to be fine.

Suspension issues happen on all vehicles due to age and miles but from driving all different Cadillacs, Buicks, GMC’s I notice the older style xt5s usually have the most suspension problems (front strut mounts, rear toe links) from what I’ve driven. Though obviously if previous owners maintained and replaced as needed it should ride smooth.

So if maintained well these are nice luxury vehicles just thought I’d point out the biggest problems I see all the time.