First M5 -- What 1st? Qs??

So I just bought my first 5 series.

An e34 M5.... 1990, it came over from Japan.

VIN: WBSHD910X02899604 (VIN DECODERS?)

Can anyone tell me where this car originated from? What is special or different about it compared to USDM cars?

I brought it to the local BMW dealer to get the valve adjustment and fluids changed out. Driving it there it seemed to stall out but it continued to run, just that the throttle stopped responding to my inputs... anyone answer this? i would accelerate, and it would just stop like it stalled and the engine RPMs would drop and a couple light on the dash would turn on, ABS, etc, and if I hit the gas...NOTHING... but if I waited or down shifted the car would respond to throttle inputs again. Any ideas.

Car has NOLOGY wires, Supersprint exhaust, and Momo wheel, and is lowered with BBS rims. The dash says in has 36,000km. No red lights etc on. According to the BMW dealer its original.

What should I do next to get the max performance gain? Where can I get a strut bar and sway bars and antiroll equipment for my M5? What else should I have done while its at the dealer. This car will be my daily racer and driver, as my 450Hp Rx7 is now not street legal.

I own a performance shop, but we specialize in Jap Imports. I want to start carrying BMW tuners parts, so anyone looking for a Western Canada dealer contact me.

I look forward to everyones replies, thank you in advance.

If you don't get your answers here, head over to M5board.com and check out the E34 M5 forum. Congratulations on your car!

Unfortunately the VIN decoder that I have only works for USDM cars.

Not to flame, but... You bought a 1990 M5 from Japan and didn't know what it had on it? Based on your post it sounds like you bought it sight-unseen, without a test drive. Am I right on that?

I don't think that this specific car makes for a good 'first 5 series.' The number of people who are qualified to work on it are few and far between, and charge a premium for their services. There are plenty of hacks out there who will do more harm than good if you bring it to them.

On the bright side...Parts should be fairly easy to get because it shared a lot of components with its lesser 5 series brethren, and that engine was made in fairly high quantities (for an M engine) and the basic architecture was used for the 5, 6 and 7 series.

You seem to have a background in the auto industry, which should help, but unless you got a screaming deal on the car, or you just have money to burn, I don't think this car will suit you as a 'daily racer and driver.' (Do you race daily?)

My family just bought a '91 M5. We bought it from my dad's employer who owns his own racing team so the car was babied for years. It has the Bavarian Autosport tuner chip, and ABE racing rims. I was wondering what we should do next to get the most bang for our buck. I was thinking sway and strut bars for sure and a K & N racing air filter. I was hoping some of you guys could lead me in the direction of a good performance parts dealer, and give me some insight as to what we should do next.