hi Ian,
Seeing I won't have time to retype my write up (it was about 1,5 pages) I'll comment on the suspension only as you almost drove the same cars as I have (apart from the new Golf then). I've test driven all these cars on the same bad road. Every 2-4 metres there is a new sheet of concrete separated by black stuff (tar?)they pour in between. Needles to say every single sheet has an annoying height difference only more annoying being the sheer amount of sheets you have to travel over. I hope you can relate to this type of road.
Let's start with the V40 1.6 petrol (16 inch wheels):
The V40 was pretty good in the front. It was fairly soft, the seats were the best I've ever sat in apart from the non-adjustable head support. And, the 1.6 engine was so quiet. I feel the Volvo is noticeably quieter than the Lexus or any other car I have driven to date. Is it just me, or was the Volvo wobbly in the front? The kind of feeling you'd get with under inflated tires. Anyway I digress.
But, oh my, in the back the suspension was so different. The rear axle took a nasty beating when going over every small short bump (not a speed bump mind you). I don't know why they stiffened up the rear so much but it was definitely far too firm for our type of roads. The worst were recessions (so a"pothole") over the entire width of the road. Imagine a sewer tube cut in half kind of pothole. My friend described that as "stomach in throat feeling" when we crossed its path.
Audi A3 1.4 latest model (also 16 inch wheels although I'm not 100% sure):
This car was fun to drive! The suspension was not really soft, but not harsh or firm either. I'd go with normal. Sure the back was a tad harder than the front as in most cars. At the front the ride was pretty good, at the rear still more than acceptable. I feel this suspension is very close to the Lexus IS 300h. Well balanced indeed.
Only the Lexus's is a bit softer in the back (sedan advantage perhaps). The seats though were too hard and no comfort seats were available. Also the angle of the seat was non-adjustable. That and the price crossed it of my list. But the Audi was definitely a good drive and never left you feeling, auch, that bump hurt.
VW Golf 1.4 latest model (don't remember wheel size. Was definitely not over 16"):
This car's standard suspension was very soft compared to the other cars. It was one of the first things me and my friend said. I just wish I had not forgotten my tire meter. It took every bump brilliantly. Even hard bumps, recessions across the entire width of the road (where I thought the Volvo would get damaged by sooner or later), were a non-issues. Yes, the trade off is steering precision and you lose an engaging drive. Fit this car with the semi-active magnetic ride suspension to harden it up when wanted and it will be very, very good.
Now for the IS 300h (17" wheels):
Suspension wise I'd say it is on par with the Audi. I'd have to drive them back to back to be sure. Lexus is a bit softer at the rear but the front is a bit more tricky to compare. The Lexus' seats are superior to the Audi's so that kind of waters down an exact comparison attempt. The Lexus never felt hard or too firm, but never plushy soft either. It is a similar kind of refinement you would find in the Audi. I'd have to test drive again but for longer than a mere hour and a half. Just to get over the initial excitement that this car might be the next one I'll break the bank for:).
Was your Lexus equipped with run flat tires? I think mine was but I'll have to check with the dealership.
ps: sorry for the probably many spelling mistakes. I hope all is well enough to be clear.