As a former Karma owner I have to disagree with you. Maybe some bugs got ironed out (but not all of them). But that's all the improvement that was made.
Even on the most recent cars the engine noise is still terrible (lawn mower-like and noisy), electric range is still below par and far less than promised and the control center is still slow and illogical. Not to mention structural design flaws: the car is too heavy, has a useless (and heavy and expensive) solar roof, adults cannot properly sit in the back, the trunk is tiny and doesn't even fit two golf bags, the wheel base is too long which makes turning in tight spots difficult and wears down the front tires, the front exhaust pipes amplify the engine noise, accelaration on the highway in stealth mode is terrible for a car with 400+ bhp.
I once had some guys pulling up next to me on the highway - at 70 mph - asking me with gestures to step on it, as they were expecting this flashy car to be quite fast. Can you imagine the look on their face (and mine) when I responded and I accelerated at a grueling slow speed. I can asure you that will never happen to me again (in my Model S Performance).
I have to politely disagree. Here's a quick snapshot of the issues the car of early 2012 faced (some of what you've mentioned) and what's been done since:
- Loud engine noise - I recall the roadshow cars sounded like a cross between a vacuum cleaner and lawn mower and was VERY intrusive at hard acceleration - Muffler 2.0 just about fixed most of the problem by Q2 2012 and a new CIU update in Q3 or thereabouts also reduced noise (by reducing ICE output and borrowing more instant power from the battery - the peak ICE demand is limited to 170hp, which is down significantly from before and much lower than the rated 240hp for the Ecotec 4banger). The engine is still louder at hard accel than say a Lexus or even a BMW, but at least now its in the same general noise band
- Driving speedo screen blackout - Problem fixed in 510 - no longer any issues with the screen resetting
- Command Center sluggishness - Dramatic improvement in the last three software updates; still not iPad quick (about 0.5s delay on initial startup), but once screens are loaded, response is instant (e.g. once radio page is loaded, you get instant haptic feedback as you hit the buttons to change stations etc)
- HV battery failure - This was really more an A123 issue, but most of the early guys like Consumer Reports got replacement batteries that have performed well so far
- Body panel gaps/alignment - Later production Karmas no longer had trunk overbite or hood alignment issues; those cars like mine that had a few of those issues were improved by dealers
- Low end chugging/creep - I think it was the 620 or 624 update that addressed creep chugging issues and how the RDM operated at low speeds; creep is now smooth and low end acceleration is also quieter and "feels" faster in both Stealth and Sport
- Wind noise/rattle from windows - The infamous 'plastic bag' noise at speeds above 60mph is now totally gone - Fisker had a bulletin out the end of last year with a part that fixed that and completely eliminated the noise
- Stranded/no start - Have never had this issue, but those that I know who have report no such issues anymore
- Bluetooth connectivity - Bluetooth now works all the time, though with certain phones, there is still a crackling; rumor was the March update had a new codec for the iphone to fix that but now we may never know!
- Backup camera not functioning - Fixed in 620 - works all the time with no black screen
- Frozen Command Center - Fixed completely in 510. Never had this happen to me, but others have reported this and now it appears to be fixed
- Sluggish acceleration - Fisker did some slight of hand here with acceleration, pulling more power from battery at initial acceleration than it did in the early cars to reduce noise; that said, the car is still comparatively slow to other $100K cars. However, we all knew the stats going into our purchase - they didn't change! Published stats 0-60 in 6.3s in Sport, 7.9s in Stealth. Various car mags have actually reported better numbers (I think MT or Automob mag had 0-60 in 5.9s and 7.5s respectively).
- Check engine light - I've yet to see this come on after I've been on 510.
- Loud charging fans/delayed charging - Also fixed in 510. No longer need to wait for fans to turn off to charge - just plug and go; works like a charm. Also fans are better modulated now so they don't stay on as long or turn as loudly as before
- Fires (haha, sorry, had to include) - fuse and fans replaced!
As for your other complaints/issues:
- electric range - I know people have issues with this - haven't gotten 50 miles on a charge, but I regularly get 39-43 miles per charge depending on how fast I drive and the topography; this is actually a pleasant surprising considering the EPA rated it at only 33 miles (imagine your ICE car with an MPG of 33mpg - ICEs almost NEVER get that high in real life; ditto on the Model S - the Karma actually gets much much higher than the EPA rating in the real world)
- car weight - again, this was known before the first customer cars were delivered; weight matters less in absolute terms - the Karma still handles phenomenally as a GT
- solar roof - agree - mostly decorative, but definitely a conversation starter
- interior space - again, not muched changed from the concept car in 2009 to the production car - a known commodity going into a purchase. I personally haven't had any problems with it - a couple of my 6' friends are fine sitting in the back for short trips; I've always liked the 'cockpit' feel of the four seat pods; you really didn't expect this to be an aftermarket upgrade/change did you?
- trunk space - again, a known commodity before delivery of the cars; you didn't expect Fisker to have an aftermarket change to this either did you?
- long wheel base - again, nothing here is a surprise - the long wheel base is what gives the Karma part of its great looks and handling
Given the car that was delivered in early 2012 and what I have now, the Karma is much improved. Had they delivered today's car last year, the story for the Karma and FA would be quite different.