Ali chassis.???

[Dualist]

Need to pick you brains a little, has anyone built one of these cars with an ali chassis at all.? If not why not.? Is it just cost.?

I know I'll have to stiffen things up a little (I was going beef it up even if it was steel). I was hoping to get the steel this week, but steady day at work and my mind wonders so looking at getting a quote for some ali instead.

But what grade should I get.? I know some of the bike chassis guys (spondon) use 7020 which doesn't need treating after welding, but if I use a more 'regular' grade ali and stiffen it up enough could I get away with out getting it heat treated.? And if I did get it heat treated would I need to make a massive jig to hold it together.? (already sounding like a nightmare).

Thanks in advance for your input

Dave.