Ok, I wasn't thinking about the ground pounding sound at a cruise , however I'll take it up a notch with since it's an unlimited budget might as well fit a three position switch, on/off/auto.  

I would build my 65 Imp like a old 60s/70s street racer.Rockcruisher/396or427 big block.Some old keystones or slot mags. My camaro would have a 335 tbi v-8 and a fresh paint job.  

Unlimited:
I'm a simple guy....

I'd build a tube frame for my '59 VW beetle to hold a supercharged 392 Hemi with a four-speed, and Olds rearend and a straight axle.

Or... I'd build a pro-touring triple-black '77 Lincoln continental four- door  with twin turbos, a six-speed with a GV unit and I'd run it in the Silver State Classic.


The $10Gs:

I'd put some better suspension under my '73 Satellite and add a GV and do the interior. I'd like to do a '70s hi-jacker style that handled. Maybe a Watts-link for the  rear or something.... add wheels and tires, press the gas, and go.  

Unlimited budget:
1970 Plymouth Satellite station wagon
BODY MODS
Converted to a two door using the door frames, quarter panels, and fenders from a two door donor.  I would have the fenders, door skins, and tailgate molded from carbon fiber.  I would then have a nose, hood (with air grabber), and wing for a Superbird molded from carbon fiber.  I'd shorten the wing to protrude six inches above the roof, while leaving the adjustability.  I would shave the drip rails and all exterior protrusions.  I would double hinge the hoos so that it could be opened from the front or the rear.   The color would be a Honda motorcycle hue called Asphalt.  The exhaust would exit in front of the rear tires.  I would open up the quarter panel scoops and duct cold air to the rear brakes.
SUSPENSION
I'd integrate the XV Motorsports independent rear suspension setup and the coilover front suspension from Magnum Force.  Brakes would be aluminum discs encompassed by electro magnets utilizing Lenz's Law (extreme braking action causing no heat or friction).  I'd use 18 inch Mopar steel wheels (from a current LX platform police car) and have them widened to 8 inches in the front and 10 inches in the back.  
DRIVETRAIN
I'd power it with a 392 Crate Hemi to which I would add twin turbos and a mega chiller setup of my own design.  Transmission would be a T56 beefed up to handle the power level (around 1000hp).  
INTERIOR
I would relocate the batteries, the nitrous tanks and the air conditioning compressor to the pit under the rear floor where the third row seat is located.  I'd go with the front seats out of a current Jeep Grand Cherokee SRT-8 and rework them so that the HVAC could be routed through the vented leather.  The dashboard would be replaced with a touch screen LCD display that would be tied into a compact computer tied into ECM with navigation, internet connectivity, and controlling the entertainment system.  The mirrors would be replaced with cameras which would be displayed on the dash screen.  The instruments would be displayed on a HUD on the windshield.  The glass would be replaced with electro-gradient tint (tint that is adjustable via electric current flow).  

Just imagine the looks on the sports car guys faces when they get spanked by a land yacht!



$10,000.00 Budget
1970 Plymouth road runner
426 low deck stroker (400 B engine with an offset ground crankshaft), Demon 850 carb, Edelbrock RPM heads, aluminum radiator, electric fans, electric water pump, Accel 300+ ignition and coil, Pistol Grip A833 4 speed transmission, 8 3/4 rear with 3.73 gears, police rally wheels with dog dish hubcaps.  That's where I am now with a tad under a grand invested in it (including the original purchase).  Plans for the future are blue suede paint with gun metal gray stripe, finish the body work and create a custom dash board.  
Out of ten thousand, I should have enough left over to build a 77ish GM Monza type car for the One Lap of America.