Hyundai i30 2015 vs Golf Estate 2014

[GKirk]

I currently own a Hyundai i30 1.6 Diesel (65 reg).

At the last MOT it had a lot of corrosion advisories and the (trusted) mechanic advised I might be best getting rid of it before its next MOT:

Front Sub-frame corroded but not seriously weakened (5.3.3 (b) (i))
Rear Sub-frame corroded but not seriously weakened (5.3.3 (b) (i))
Offside Front Suspension arm corroded but not seriously weakened (5.3.3 (b) (i))
Nearside Rear Lower Suspension arm corroded but not seriously weakened (5.3.3 (b) (i))
Offside Rear Lower Suspension arm corroded but not seriously weakened (5.3.3 (b) (i))

PHOTOS OF UNDERSIDE i30

I only do 4500 miles a year and have another car in the household so I'm looking at relatively low cost solutions.

I've a relative replacing their Golf Estate 2.0 Diesel DSG (14 reg) as it can't get into the local LEZ (not a concern for me). The Golf is serviced at the same garage as the i30 and the mechanic hasn't raised any concerns regarding it, minimal advisories, no mention of corrosion. I can get the Golf for trade-in value and I know its been well looked after so it's a tempting option. However, it's obviously no spring chicken. I don't mind paying for repairs to keep it on the road but I don't want to trade one corroded subframe for another!

PHOTOS OF GOLF UNDERSIDE

I can see rust on both cars, is the i30 rust significantly worse than the Golf?

I've watched a couple of videos regarding sub frame rust but they haven't been of much use in helping me differentiate between the two...

[ZX10R NIN]

They look almost the same to me, I'd get the underside of the i30 cleaned & treated.