Our Panda, being a second car - and a bit of a cosseted project for me - doesn't do a high annual mileage. I just run her on the standard plugs - some call them "copper" - which I remove and check gaps at service time because wide plug gaps are a strain on HT components and I wish to avoid that - Incidentally DO NOT attempt to gap "slim electrode" plugs, it's a big No No, they can be damaged by doing this. You just fit them as they come out of the box but examine them visually before you do so in case they've been damaged in transit (unlikely though) - It used to be that removing plugs annually, and maybe using a little Copa slip, or Aluslip if an aluminium head, was a good thing to do because it greatly reduced the chances of plugs corroding their threads. Nowadays most plugs have a sacrificial plated finish on their threads - looks like a chrome or nickel plating but apparently it's actually a sacrificial coating which is designed to shear so making removal after maybe 6 years or more less of a problem - not uncommon on modern extended interval servicing. "Standard" plugs can be bought very cheaply these days I think mine were only about £3.00 each last ones I bought. In fact all the family cars Our Panda, the Punto, Jazz and Astra run ordinary plugs without any problems. The Ibiza runs iridium/platignum or whatever they are because the coils are absolute swines to get out without the special puller and "the knowledge" so my local indy does them for me. First set done earlier this year at commencement of her 7th year.
Brake fluid change? I have a boiling point tester so I test every year and change when the tester tells me it needs it. If I didn't have one of these I'd be doing a complete flush through every second year and certainly within the 3 years. Trouble with brake fluid is it's hygroscopic - no that's not a spelling error - which, as many of us will know - means it absorbs moisture. Now this is very bad for several reasons but the two biggies are that water boils at a considerably lower point than brake fluid and brakes, say on a long hill descent or extreme emergency stop, can get very hot indeed such that the caliper/brake cylinders can get hot enough to boil the water content in the fluid. If it boils it turns to steam and steam is a gas so is compressible. What you as the driver will find is that your brake pedal starts out good and hard because both the fluid and water content are liquid so virtually incompressible. The pedal continues to feel good during braking but then suddenly, with virtually no warning, goes to the floor as the water content turns to steam. It's a terrifying experience and has resulted in fatalities in the past. The other thing worth thinking about is that if you run with old fluid in the system the water content will corrode the caliper and cylinder pistons - and today with ABS, it's not good for ABS internals either. So folks, yes to a brake fluid change every 2 years or so. A wee smear of anti seize around the nipple threads while you're at it goes a long way to preventing bleed nipples seizing in place too. Clutch fluid isn't under the same stress as brake fluid so, if it's looking clean and not dark in colour, it's probably Ok to leave it. On the other hand bleeding it isn't difficult as long as you don't let air get into the system and remember the pedal will need to be pulled back up from the floor after you've pushed it down with the bleed nipple open because it uses the clutch cover assembly spring to return it under normal operation.
I'm a bit obsessed with pollen filters too, a much ignored component. Our Panda, my boy's Punto and my daughter in law's Jazz, all had absolutely disgusting cabin filters first time I serviced them. I think it unlikely they had ever been changed from new. Sometimes I think the manufacturers are guilty in that they make it a very difficult thing to do. The Panda (It's a 169) is not too bad to access. The Punto, which is the later model built after 2012 has to have it's element sort of folded up into a shape approaching a triangle to get it in and then straightened out again when in place with a slim long screwdriver. It's Ok to do once you figure it out but the first time I did it it took me ages and I ended up with a very sore back. The Ibiza is pretty good, there's a removable cover in the passenger footwell which just releases with sliding catches, no tools needed and the filter almost falls out. The new one goes back in just as easy. But the pick of the bunch is the Jazz which is a peach, you just pull part of the glovebox out and the filter element comes out through the glovebox. You can do it all sitting in the passenger seat. Ten out of ten for that one Honda. I'm going on a bit about this because I've heard people say stuff like "my cabin filter is horrible to do so I just leave it alone. It's still blowing air anyway". What those people need to think about is that most heater fan motors have a range of speeds you can select and to achieve the slower speeds what they do is run the current through a resistor bank, which gets hot! and the slower the speed you select the more resistor it uses so it gets even hotter! I'm talking pretty hot here, you would burn your fingers if you touched it. So how do most of them shed this heat? they stick them in the airflow trunking for the heater blower and let the air flowing through the heater system carry the resistor heat away. Blocked up cabin filters will restrict air flow to this vital resistor pack - which are well known for burning out anyway - and so the life of the resistor pack will be compromised. I check the cabin filters in the "family fleet" every service - so pretty much every year - and mostly I find they last about 2 years on average but I have found my boy's Astra sometimes needs one yearly but he does rack up the miles as he uses it for business. Mostly resistor packs are a bit of a Phaf to change so the longer you can make them last the better.
I see your quoted prices for the filters etc and you can virtually half them if you buy quality after market products and really not compromise on quality. Have an ask around for your local factor - google for Motor Factors/Car Parts in your area. Euro Car Parts have branches all over the place but I find my two locals SRS and Pentland Components nearly always undercut their prices without me asking. Halfords can sometimes be surprisingly economical and my local branch are very helpful. Local trade factors will be supplying the trade around you so it's very unlikely you'll be supplied with anything "dodgy" You need to be a bit more careful if you buy from an "accessory" shop or from some online suppliers. If you're looking at online stuff then go to their website and see what else they are selling. If it's all car stuff and they seem to have a large and diverse stock on offer you'll probably be Ok. If they're selling a few oil filters, maybe some wiper blades, along with sun glasses and hemorrhoid creams, probably better to look elsewhere?