The engine roar is not necessary the engine is under super heavy load. More of the effect of the CVT keep the engine at a specific RPM. Power is not an issue. I can still go 70 mph uphill easily around the Magic Mtn area.
I put some velcro on the bottom of the scangauge and mounted it on the top of the steering column right behind the steering wheel. Since I'm 6 ft I can see it just fine between the spokes of the steering wheel. Then I routed the cable just down under the dash right there and plugged it into the OBD plug there.
Since this has morphed into a scanguage thread ... why should I add a gauge to display RPMs, engine temp, instantaneous MPG and SOC. My dash displays instantaneous MPG and SOC. I couldn't care less about RPM. I'm not rev matching a manual transmission and the rev limiting software takes care of that use of the Tach in older cars.) I consider a Tach in most cars a needless expense and waste of good dash space. The temp will trigger a lite if it gets too hot. So I'm not seeing any information from the scanguage I'd be wanting to react to. Help me understand why you choose those and how you use it in every day driving. (I have a OBD2 reader. Used it on a dozen cars. I've driven cars with telemetry that cost more than an entire v and with lots more info displayed than mere passenger cars. Different situation. I've also driven cars (early VW and Model A) that had almost no gauges or display lites.)
FHVA syndrome. First Hybrid Vehicle Anxiety... It'll pass. Just drive it like a normal vehicle. I actually "Plan" a long road trip with any new vehicle I happen to obtain. By the end of it, I always feel more "bonded" and familar with the vehicle. With my Prius, it was Oregon to The California Redwoods. By the time I got back, Any FHVA I might of been suffering from was gone.
I wouldn't use the scangauge for MPG or SOC. As you mentioned, it's already displayed on the dash. I like the RPMs for info. but what I really want is engine temp displayed. I feel that by the time the temp triggers the light on the dash, it's a bit too late to react besides pulling over and watching steam come out from the engine bay. Would I use this every day? absolutely not. there is no need. But I would have it attached and keep an eye on the readings during my long road trips. This is why I have opted to spend a little change on the Gauge. it's useful information to me. it maybe be worthless to you, but for peace of mind it's worth it for me.
The RPM is nice because it basically gives you power output and I can use that to keep the RPMs from leaving the peak BSFC area while on the highway. Temp is nice in the winter as I can modulate the heater to keep the engine from getting cold in low load situations.