Mountain driving
 

I recently did a fair amount of mountain driving and boy does everything get hot, you can almost smell it on the car when you get out! I'm guessing that's probably hot oil on the turbo? One thing I did notice is that the needle temperature gauge moved a little higher, not a lot, but definitely a little. I'm not sure but I don't think the cooling system was serviced recently so I'll probably flush that out sometime soon. Do I have to put Volvo coolant back in there or will any universal fluid do?

Also the transmission seems to behave a little odd. Going up hill if I wasn't using geartronic (GT) the engine would be doing high revs while apparently in 5th gear suggesting some kind of slipping? Then I started to use the GT all the time, mostly 4th and 3rd gears. Shifting down from 4th to 3rd is usually fine but under engine braking conditions it would give three little judders before smoothing out. Change down from 3rd to 2nd for engine braking is not smooth at all and makes quite a jolt on the transmission (so I stopped doing that so much but on some roads you really want it). Normally the transmission is fine but I was worried that perhaps it is getting too hot, would it be worth installing a transmission cooler? The Volvo part #9499131 is $420 which seems like an awful lot, has anyone installed an aftermarket one made by someone else? I can buy one from U-Haul for $46 :)